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Sample records for azo dyes

  1. Anaerobic azo dye reduction

    OpenAIRE

    Zee, van der, KG Kristoffer

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo dyes and their breakdown products are toxic and/or mutagenic to life. To remove azo dyes from wastewater, a biological treatment strategy based on anaerobic reduction of the azo dyes, followed by aerobic transfo...

  2. Anaerobic azo dye reduction

    NARCIS (Netherlands)

    Zee, van der F.P.

    2002-01-01

    Azo dyes, aromatic moieties linked together by azo (-N=N-) chromophores, represent the largest class of dyes used in textile-processing and other industries. The release of these compounds into the environment is undesirable, not only because of their colour, but also because many azo

  3. Synthesis of azo pyridone dyes

    Directory of Open Access Journals (Sweden)

    Mijin Dušan Ž.

    2011-01-01

    Full Text Available Over 50% of all colorants which are used nowdays are azo dyes and pigments, and among them arylazo pyridone dyes (and pigments have became of interest in last several decades due to the high molar extinction coefficient, and the medium to high light and wet fastness properties. They find application generally as disperse dyes. The importance of disperse dyes increased in the 1970s and 1980s due to the use of polyester and nylon as the main synthetic fibers. Also, disperse dyes were used rapidly since 1970 in inks for the heat-transfer printing of polyester. The main synthetic route for the preparation of azo dyes is coupling reaction between an aromatic diazo compound and a coupling component. Of all dyes manufactured, about 60% are produced by this reaction. Arylazo pyridone dyes can be prepared from pyridone moiety as a coupling component, where substituent can be on nitrogen, and diazonim salts which can be derived from different substituted anilines or other heterocyclic derivatives. In addition, arylazo dyes containing pyridone ring can be prepared from arylazo diketones or arylazo ketoesters (obtained by coupling β-diketones or β-ketoesters with diazonim salts by condensation with cyanoacetamide. Disazo dyes can be prepared by tetrazotizing a dianiline and coupling it with a pyridone or by diazotizing aniline and coupling it with a dipyridone. Trisazo dyes can be also prepared by diazotizing of aniline and coupling it with a tripyridone or by hexazotizing a trianiline and coupling it with a pyridone. The main goal of this paper is to give a brief review on the synthesis of arylazo pyridone dyes due to the lack of such reviews. In addition, some properties of arylazo pyridone dyes as light fastness and azo-hydrazon tautomerism are disccused.

  4. Azo-hydrazone tautomerism of aryl azo pyridone dyes

    Directory of Open Access Journals (Sweden)

    Mirković Jelena M.

    2013-01-01

    Full Text Available In the last three or four decades disperse dyes derived from pyridones (in particular azo pyridone dyes have gained in importance, and are widely used in various fields. These compounds have excellent coloration properties, and are suitable for the dyeing of polyester fabrics. Basic features of these dyes are simplicity of their synthesis by diazotation and azo coupling. They generally have high molar extinction coefficient with medium to high light and wet fastness. The absorption maxima of these dyes show their visible absorption wavelength ranging from yellow to orange, which can be attributed to poorly delocalized electrons in the pyridone ring. However, there are several dyes with deep colors such as red or violet. Pyridone dyes with alkyl and aryl groups in ortho position to azo group show 2-pyridone/2-hydroxypyridine tautomerism, while those containing OH and NHR groups conjugated with the azo group show azo-hydrazone tautomerism. Determining azo-hydrazone tautomerism could be therefore interesting, since the tautomers have different physico-chemical properties and most importantly different coloration. The literature on azo-hydrazone tautomerism, determination of equilibrium position, and investigation of substituent and solvent influence on tautomerism has been summarized in the presented review. The general conclusion is that the equilibrium between two tautomers is influenced by the structure of the compounds and by the solvents used. The tautomeric behavior patterns of the arylazo pyridone dyes in the reviewed literature has been studied using various instrumental techniques, including FT-IR, UV-vis, and NMR spectroscopy. The quantum chemical calculations related to the azo-hydrazon tautomerism have also been included. A large number of pyridone dyes exist in hydrazone form in solid state, while in solvents there is a mixture of tautomers. In addition, the X-ray single-crystal diffraction data analysis of some commercial pyridone

  5. Integrated sequential anaerobic/aerobic biodegradation of azo dyes

    OpenAIRE

    Tan, N.C.G.

    2001-01-01

    Azo dyes constitute a major class of environmental pollutants accounting for 60 to 70% of all dyes and pigments used. These compounds are characterized by aromatic moieties linked together with azo groups (-N=N-). The release of azo dyes into the environment is a concern due to coloration of natural waters and due to the toxicity, mutagenicity and carcinogenicity of the dyes and their biotransformation products. Therefore, considerable attention has been given to evaluating the fate of azo dy...

  6. 40 CFR 721.5917 - Phenyl azo dye (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenyl azo dye (generic). 721.5917... Substances § 721.5917 Phenyl azo dye (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenyl azo dye (PMN P-02-17) is subject...

  7. 40 CFR 721.9717 - Azo monochloro triazine reactive dye.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Azo monochloro triazine reactive dye... Substances § 721.9717 Azo monochloro triazine reactive dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an azo monochloro...

  8. 40 CFR 721.4594 - Substituted azo metal complex dye.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted azo metal complex dye. 721... Substances § 721.4594 Substituted azo metal complex dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a substituted azo metal...

  9. Degradation of azo dyes by environmental microorganisms and helminths

    Energy Technology Data Exchange (ETDEWEB)

    Kingthom Chung; Stevens, S.E. Jr. (Memphis State Univ., TN (United States). Dept. of Biology)

    1993-11-01

    The degradation of azo dyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number of anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascaris lumbricoides and the cestode Moniezia expanza have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysoporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dye is proposed and future research needs are discussed.

  10. Characterization of the decolorizing activity of azo dyes by Bacillus subtilis azoreductase AzoR1

    OpenAIRE

    Montira Leelakriangsak; Sukallaya Borisut

    2012-01-01

    The product of the Bacillus subtilis gene azoR1 is annotated as a putative azoreductase, production of which isinduced in response to thiol-reactive compounds. Here we report on the decolorization of four azo dyes by azoreductaseactivity. The ability of overexpressed AzoR1 strain ORB7106 to catalyze decolorization of azo dyes was investigated on agarplates and in liquid cultures. The decolorization efficacy of a mutant, ORB7106, which has lost negative control of azoR1expression, was signific...

  11. Re-evaluation of azo dyes as food additives

    DEFF Research Database (Denmark)

    Pratt, Iona; Larsen, John Christian; Mortensen, Alicja;

    2013-01-01

    Aryl azo compounds are widely used as colorants (azo dyes) in a wide range of products including textiles, leather, paper, cosmetics, pharmaceuticals and food.As part of its systematic re-evaluation of food additives, the European Food Safety Authority (EFSA) has carried out new risk assessments of...... allazo dyes permitted in food. EFSA has also evaluated a number of azo dyes found illegally in food in recent years, including Sudan dyes, Para Red and Orange II. The re-evaluation of all food colours, including the azo dyes,was considered high priority (i) because colorants were among the first...... authorisation for Red 2G, new labelling provisions and reductions in the Maximum Permitted Levels for some azo dyes in food. Copyright © 2013 Published by Elsevier Ireland Ltd....

  12. Biodegradation of bioaccessible textile azo dyes by Phanerochaete chrysosporium

    OpenAIRE

    Martins, Maria Adosinda; Ferreira, Isabel C.F.R.; Santos, Isabel; Queiroz, Maria João R. P.; Lima, Nelson

    2000-01-01

    Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation assays were obtained from a pre-growth medium (PAM), containing one of the synthesised dyes. The results of the dye biodegradation assays were eval...

  13. An Interdisciplinary Experiment: Azo-Dye Metabolism by "Staphylococcus Aureus"

    Science.gov (United States)

    Brocklesby, Kayleigh; Smith, Robert; Sharp, Duncan

    2012-01-01

    An interdisciplinary and engaging practical is detailed which offers great versatility in the study of a qualitative and quantitative metabolism of azo-dyes by "Staphylococcus aureus". This practical has broad scope for adaptation in the number and depth of variables to allow a focused practical experiment or small research project. Azo-dyes are…

  14. Modification of azo dyes by lactic acid bacteria

    Science.gov (United States)

    Identification of microorganisms capable of utilizing azo dyes have been an area of significant interest due to their role in the treatment of waste water derived from the textile industry. The ability of L. casei LA1133 and L. paracasei LA0471 to modify the azo dye tartrazine was recently document...

  15. Biodegradation of textile Azo Dyes by Phanerochaete chrysosporium

    OpenAIRE

    Ferreira, Isabel C. F. R.; Santos, Isabel M.; Queiroz, Maria João R. P.; Lima, Nelson

    1998-01-01

    Azo dyes are used extensively in the textile and dyestuff industries and effluents from these industrial processes are usually resistant to biological treatment. Textile azo dyes with bioaccessible groups such as guaiacol and 2,6-dimethoxyphenol, for lignin-degrading fungus as P. chrysosporium were synthesised.

  16. Synthesis and characterization of textile azo dyes derivatives of methoxyphenols

    OpenAIRE

    Ferreira, Isabel C. F. R.; Queiroz, Maria João R. P.

    1999-01-01

    Azo dyes are used extensively in the textile and dyestuff industries and effluents from these industrial processes are usually resistant to biological treatment. Textile azo dyes with bioaccessible groups such as guaiacol (2-methoxyphenol) and 2,6--dimethoxyphenol, for lignin-degrading fungus were synthesized using aminobenzoic and aminosulfonic acids as diazocomponents.

  17. Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guangfei [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Wang Jing, E-mail: wangjingbio@yahoo.cn [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China); Lu Hong; Jin Ruofei; Zhou Jiti; Zhang Long [Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, School of Environmental and Biological Science and Technology, Dalian University of Technology, Linggong Road No. 2, Dalian 116024 (China)

    2009-11-15

    The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L{sup -1}, the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

  18. Effects of reduction products of ortho-hydroxyl substituted azo dyes on biodecolorization of azo dyes

    International Nuclear Information System (INIS)

    The mediated effects of reduction products of some ortho-hydroxyl substituted azo dyes on biodecolorization were investigated. The results indicated that the addition of reduction products could effectively accelerate dye decolorization by Shigella sp. QRZ-1. The best accelerating effect was obtained with the addition of reduction products of Acid Red 14 (AR14), resulting in an over 3-fold increase in decolorization efficiency of many azo dyes. In sequencing batch reactor experiments, the accelerating effect of reduction products of AR14 was more obvious (1.5-fold) during the startup of the system. When the dye concentration was increased to 500 mg L-1, the accelerated decolorization efficiency was still maintained around 95%. The presence of AR14 in the feed enhanced the decolorization performance of anaerobic sludge, indicating that the strategy may be beneficial for practical application. 1-Naphthol-2-amino-4-sulfonic acid, which is one of the reduction products of AR14, may function as redox mediator to speed up azo dye biodecolorization.

  19. A New Generation of Glycoconjugated Azo Dyes Based on Aminosugars

    Directory of Open Access Journals (Sweden)

    Lorenzo Guazzelli

    2015-01-01

    Full Text Available The third generation of glycoconjugated azo dyes (GADs was prepared linking monoazo dyes to 6-amino-6-deoxy-d-galactose or 6′amino-6′-deoxylactose through mixed amido-ester connections. The complementary conjugation reactions were studied using the succinyl derivative of either the acetal protected aminosugar or the azo dye. Target “naturalized” GADs were obtained after acid hydrolysis of the acetal protecting groups present on the sugar moiety.

  20. Re-evaluation of azo dyes as food additives

    DEFF Research Database (Denmark)

    Pratt, Iona; Larsen, John Christian; Mortensen, Alicja;

    2013-01-01

    Aryl azo compounds are widely used as colorants (azo dyes) in a wide range of products including textiles, leather, paper, cosmetics, pharmaceuticals and food.As part of its systematic re-evaluation of food additives, the European Food Safety Authority (EFSA) has carried out new risk assessments of...... additives to be assessed by the Scientific Committee on Food, many years ago, (ii) because of concern regarding possible health effects of artificial colours arising since the original evaluations.Concerns includedbehavioural effects in children, allergic reactions, genotoxicity and possible carcinogenicity...... allazo dyes permitted in food. EFSA has also evaluated a number of azo dyes found illegally in food in recent years, including Sudan dyes, Para Red and Orange II. The re-evaluation of all food colours, including the azo dyes,was considered high priority (i) because colorants were among the first...

  1. Universal dark quencher based on "clicked" spectrally distinct azo dyes.

    Science.gov (United States)

    Chevalier, Arnaud; Hardouin, Julie; Renard, Pierre-Yves; Romieu, Anthony

    2013-12-01

    The first synthesis of an heterotrifunctional molecular scaffold derived from the popular DABCYL azo dye quencher has been achieved. The sequential derviatization of this trivalent azobenzene derivative with two other nonfluorescent azo dyes (Black Hole Quencher BHQ-1 and BHQ-3) and through effective reactions from the "bioconjugation chemistry" repertoire has led to an universal dark quencher (UDQ). This "clicked" poly azo dye is able to turn off an array of fluorophores covering the UV/NIR (300-750 nm) spectral range. PMID:24215300

  2. Reduction of Polymeric Azo and Nitro Dyes by Intestinal Bacteria

    OpenAIRE

    Brown, Joseph P.

    1981-01-01

    The O2-sensitive reduction of high-molecular-weight aromatic azo and nitro dyes by intestinal bacteria appears to be mediated by low-molecular-weight electron carriers with Eo′ = −200 to −350 mV. This process may allow the design of polymeric azo prodrugs for specific release of certain aromatic amines in the colon.

  3. Azo dye decolorization assisted by chemical and biogenic sulfide

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, Dorian [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico); Cervantes, Francisco J. [División de Ciencias Ambientales, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa de San José 2055, San Luis Potosí 78216 (Mexico); Buitrón, Germán, E-mail: gbuitronm@ii.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Unidad Académica Juriquilla, Instituto de Ingeniería, Universidad Nacional Autónoma de México, Blvd. Juriquilla 3001, Querétaro 76230 (Mexico)

    2013-04-15

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection.

  4. Azo dye decolorization assisted by chemical and biogenic sulfide

    International Nuclear Information System (INIS)

    Highlights: ► Azo dyes were reduced efficiently by chemical and biogenic sulfide. ► Biogenic sulfide was more efficient than chemical sulfide. ► There was no competition between dyes and sulfate for reducing equivalents. ► Aromatic amines barely affected the sulfate-reducing process. -- Abstract: The effectiveness of chemical and biogenic sulfide in decolorizing three sulfonated azo dyes and the robustness of a sulfate-reducing process for simultaneous decolorization and sulfate removal were evaluated. The results demonstrated that decolorization of azo dyes assisted by chemical sulfide and anthraquinone-2,6-disulfonate (AQDS) was effective. In the absence of AQDS, biogenic sulfide was more efficient than chemical sulfide for decolorizing the azo dyes. The performance of sulfate-reducing bacteria in attached-growth sequencing batch reactors suggested the absence of competition between the studied azo dyes and the sulfate-reducing process for the reducing equivalents. Additionally, the presence of chemical reduction by-products had an almost negligible effect on the sulfate removal rate, which was nearly constant (94%) after azo dye injection

  5. REMOVAL OF AZO DYES BY THE ACTIVATED SLUDGE PROCESS

    Science.gov (United States)

    The Water Engineering Research Laboratory, Office of Research & Development, U.S. Environmental Protection Agency (EPA) is conducting research designed to develop techniques for predicting the fate of azo dyes in typical wastewater treatment systems which are treating wastewater ...

  6. Photobleaching effect in azo-dye containing epoxy resin films: the potentiality of carbon nanotubes as azo-dye dispensers

    Science.gov (United States)

    Díaz Costanzo, Guadalupe; Goyanes, Silvia; Ledesma, Silvia

    2015-04-01

    Azo-dye molecules may suffer from bleaching under certain illumination conditions. When this photoinduced process occurs, it generates an irreversible effect that is characterized by the loss of absorption of the dye molecule. Moreover, the well-known isomerization of azodye molecules does not occur anymore. In this work it is shown how the addition of a small amount of multi-walled carbon nanotubes (MWCNTs) helps to decrease the bleaching effect in a photosensitive guest-host azo-polymer film. Two different systems were fabricated using an epoxy resin as polymer matrix. An azo-dye, Disperse Orange 3, was used as photosensitive material in both systems and MWCNTs were added into one of them. The optical response of the polymeric systems was studied considering the degree of photoinduced birefringence. Photobleaching of the azo-dye was observed in all cases however, the effect is lower for the composite material containing 0.2 wt % MWCNTs. The weak interaction between MWCNTs and dye molecules is less favorable when the material is heated. The optical behavior of the heated composite material suggests that carbon nanotubes can be potentially used as azo dye dispensers. The results are interpreted in terms of the non-covalent interaction between azo-dye molecules and MWCNTs.

  7. Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

    OpenAIRE

    Shahid Mahmood; Muhammad Arshad; Azeem Khalid; Zilli Huma Nazli; Tariq Mahmood

    2011-01-01

    Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of...

  8. Microbial fuel cell with an azo-dye-feeding cathode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Liang [Chinese Academy of Sciences, Guangzhou (China). Guangzhou Inst. of Geochemistry; Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou (China). Guangdon Key Lab. of Agricultural Environment Pollution Integrated Control; Graduate Univ. of Chinese Academy of Sciences, Beijing (China); Li, Fang-bai [Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou (China). Guangdon Key Lab. of Agricultural Environment Pollution Integrated Control; Feng, Chun-hua [South China Univ. of Technology, Guangzhou (China). School of Chemistry and Chemical Engineering; Li, Xiang-zhong [Hong Kong Polytechnic Univ., Hong Kong (China). Dept. of Civil and Structural Engineering

    2009-11-15

    Microbial fuel cells (MFCs) were constructed using azo dyes as the cathode oxidants to accept the electrons produced from the respiration of Klebsiella pneumoniae strain L17 in the anode. Experimental results showed that a methyl orange (MO)-feeding MFC produced a comparable performance against that of an air-based one at pH 3.0 and that azo dyes including MO, Orange I, and Orange II could be successfully degraded in such cathodes. The reaction rate constant ({kappa}) of azo dye reduction was positively correlated with the power output which was highly dependent on the catholyte pH and the dye molecular structure. When pH was varied from 3.0 to 9.0, the k value in relation to MO degradation decreased from 0.298 to 0.016 {mu}mol min{sup -1}, and the maximum power density decreased from 34.77 to 1.51 mW m{sup -2}. The performances of the MFC fed with different azo dyes can be ranked from good to poor as MO > Orange I > Orange II. Furthermore, the cyclic voltammograms of azo dyes disclosed that the pH and the dye structure determined their redox potentials. A higher redox potential corresponded to a higher reaction rate. (orig.)

  9. Detection of azo dyes and aromatic amines in women undergarment.

    Science.gov (United States)

    Nguyen, Thao; Saleh, Mahmoud A

    2016-07-28

    Women are exposed to several chemical additives including azo dyes that exist in textile materials, which are a potential health hazard for consumers. Our objective was to analyze suspected carcinogenic azo dyes and their degradation aromatic amines in women underwear panties using a fast and simple method for quantification. Here, we evaluated 120 different samples of women underwear for their potential release of aromatic amines to the skin. Seventy-four samples yielded low level mixtures of aromatic amines; however eighteen samples were found to produce greater than 200 mg/kg (ppm) of aromatic amines. Azo dyes in these 18 samples were extracted from the fabrics and analyzed by reverse phase thin layer chromatography in tandem with atmospheric pressure chemical ionization mass spectrometry. Eleven azo dyes were identified based on their mass spectral data and the chemical structure of the aromatic amine produced from these samples. We demonstrate that planar chromatography and mass spectrometry can be really helpful in confirming the identity of the azo dyes, offering highly relevant molecular information of the responsible compounds in the fabrics. With the growing concern about the consumer goods, analysis of aromatic amines in garments has become a highly important issue. PMID:27149414

  10. Detoxification of azo dyes by bacterial oxidoreductase enzymes.

    Science.gov (United States)

    Mahmood, Shahid; Khalid, Azeem; Arshad, Muhammad; Mahmood, Tariq; Crowley, David E

    2016-08-01

    Azo dyes and their intermediate degradation products are common contaminants of soil and groundwater in developing countries where textile and leather dye products are produced. The toxicity of azo dyes is primarily associated with their molecular structure, substitution groups and reactivity. To avoid contamination of natural resources and to minimize risk to human health, this wastewater requires treatment in an environmentally safe manner. This manuscript critically reviews biological treatment systems and the role of bacterial reductive and oxidative enzymes/processes in the bioremediation of dye-polluted wastewaters. Many studies have shown that a variety of culturable bacteria have efficient enzymatic systems that can carry out complete mineralization of dye chemicals and their metabolites (aromatic compounds) over a wide range of environmental conditions. Complete mineralization of azo dyes generally involves a two-step process requiring initial anaerobic treatment for decolorization, followed by an oxidative process that results in degradation of the toxic intermediates that are formed during the first step. Molecular studies have revealed that the first reductive process can be carried out by two classes of enzymes involving flavin-dependent and flavin-free azoreductases under anaerobic or low oxygen conditions. The second step that is carried out by oxidative enzymes that primarily involves broad specificity peroxidases, laccases and tyrosinases. This review focuses, in particular, on the characterization of these enzymes with respect to their enzyme kinetics and the environmental conditions that are necessary for bioreactor systems to treat azo dyes contained in wastewater. PMID:25665634

  11. Biosorption of Azo dyes by spent Rhizopus arrhizus biomass

    Science.gov (United States)

    Salvi, Neeta A.; Chattopadhyay, S.

    2016-05-01

    In the present study, spent Rhizopus arrhizus biomass was used for the removal of six azo dyes from aqueous solutions. The dye removal capacity of the biomass was evaluated by conducting batch tests as a function of contact time, biomass dosage, pH and initial dye concentrations. The pseudo-second-order kinetic model fitted well with the experimental data with correlation coefficients greater than 0.999, suggesting that chemisorptions might be the rate limiting step. The equilibrium sorption data showed good fit to the Langmuir isotherm model. Among the six dyes tested, the maximum monolayer adsorption capacity for fast red A and metanil yellow was found to be 108.8 and 128.5 mg/g, respectively. These encouraging results suggest that dead Rhizopus arrhizus biomass could be a potential biomaterial for the removal of azo dyes from aqueous dye solution.

  12. Novel photochromic 2,2´-bithiophene azo dyes

    OpenAIRE

    Paulo J. Coelho; Carvalho, Luís H. Melo de; Moura, João C. V. P.; Raposo, M. Manuela M.

    2009-01-01

    The photochromic behaviour of two series of 2,2’-bithiophene azo dyes in THF solutions was studied. The photochromic properties and colour constancy were strongly dependent on the substitution pattern of the dyes. Under visible irradiation (> 420 nm) while some dyes exhibited a significant change in the colour intensity others exhibited an almost stable absorption. The photokinetic parameters of these systems are described. Fundação para a Ciência e a Tecnologia (FCT)

  13. 40 CFR 721.980 - Sodium salt of azo acid dye.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Sodium salt of azo acid dye. 721.980... Substances § 721.980 Sodium salt of azo acid dye. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a sodium salt of azo acid dye (PMN...

  14. Photoinduced translational molecular mobility in solid nanostructured azo dye films

    International Nuclear Information System (INIS)

    A new mechanism controlling the molecular motion in thin azo-containing films during a photoinduced change in the surface nanorelief is found. It is shown experimentally that exposure of a solid AD-1 azo dye, deposited on a glass substrate, to incoherent linearly polarised light leads to formation of nanostructures with a characteristic size of 200 nm, which are similar to droplets of melt of this dye on the same substrate. It is shown that photoinduced mass transport in a solid AD-1 azo dye film can be explained by the mobility of molecules related to their trans-cis-photoisomerisation, which leads to film softening with subsequent formation of spherical protrusions under surface tension forces.

  15. FATE OF WATER SOLUBLE AZO DYES IN THE ACTIVATED SLUDGE PROCESS

    Science.gov (United States)

    The objective of this study was to determine the partitioning of water soluble azo dyes in the activated sludge process (ASP). Azo dyes are of concern because some of the dyes, dye precursors , and/or their degradation products such as aromatic amines (which are also dye precurso...

  16. Use of highly absorptive azo dyes in photoresist coatings

    Science.gov (United States)

    Lu, Ping-Hung; Ding, Shuji; Hannigan, T. T.; Eberly, D. E.; Kokinda, Elaine; Dixit, Sunit S.; Mehtsun, Salem; Corso, Anthony J.; Khanna, Dinesh N.

    1997-07-01

    We recently synthesized and studied a number of highly absorptive diketo azo dyes. These materials, existed in the hydrazo tautomeric forms, showed high extinction coefficients, typically (epsilon) approximately equals 25,000 - 39,000 at 365 nm. They also exhibited good solubility in common resist casting solvents such as propylene glycol monoethyl acetate (PGMEA) and ethyl lactate. The thermostability of the materials was investigated. The impact of these diketo azo dyes on i-line resist performance in terms of swing reduction, reflective notching control and lithographic performance is discussed.

  17. Toxicity assessment and microbial degradation of azo dyes.

    Science.gov (United States)

    Puvaneswari, N; Muthukrishnan, J; Gunasekaran, P

    2006-08-01

    Toxic effluents containing azo dyes are discharged from various industries and they adversely affect water resources, soil fertility, aquatic organisms and ecosystem integrity. They pose toxicity (lethal effect, genotoxicity, mutagenicity and carcinogenicity) to aquatic organisms (fish, algae, bacteria, etc.) as well as animals. They are not readily degradable under natural conditions and are typically not removed from waste water by conventional waste water treatment systems. Benzidine based dyes have long been recognized as a human urinary bladder carcinogen and tumorigenic in a variety of laboratory animals. Several microorganisms have been found to decolourize, transform and even to completely mineralize azo dyes. A mixed culture of two Pseudomonas strains efficiently degraded mixture of 3-chlorobenzoate (3-CBA) and phenol/cresols. Azoreductases of different microorganisms are useful for the development of biodegradation systems as they catalyze reductive cleavage of azo groups (-N=N-) under mild conditions. In this review, toxic impacts of dyeing factory effluents on plants, fishes, and environment, and plausible bioremediation strategies for removal of azo dyes have been discussed. PMID:16924831

  18. Equilibrium and thermodynamics of azo dyes biosorption onto Spirulina platensis

    OpenAIRE

    G. L. Dotto; M. L. G. Vieira; V. M. Esquerdo; L. A. A. PINTO

    2013-01-01

    The equilibrium and thermodynamics of azo dye (tartrazine and allura red) biosorption onto Spirulina platensis biomass were investigated. The equilibrium curves were obtained at 298, 308, 318 and 328 K, and four isotherm models were fitted the experimental data. Biosorption thermodynamic parameters (ΔG, ΔH and ΔS) were estimated. The results showed that the biosorption was favored by a temperature decrease. For both dyes, the Sips model was the best to represent the equilibrium...

  19. Removal of azo dye from aqueous solutions using chitosan

    OpenAIRE

    Zuhair Jabbar; G. Hadi Ferdoos Sami; A , Angham

    2014-01-01

    Adsorption of Congo Red (CR) from aqueous solution onto chitosan was investigated in a batch system. The effects of solution pH, initial dye concentration, and temperature were studied. Results indicated that chitosan could be used as a biosorbent to remove the azo dyes from contaminated water. Synthesize of chitosan involved three main stages as preconditioning, demineralization, deproteinization and deacetylation. Chitosan was characterized using Fourier Transform Infrared Spectroscopy (FTI...

  20. Synthesis of dis-azo black dyes for electrowetting displays

    International Nuclear Information System (INIS)

    Highlights: ► The electrowetting technology with high reflectivity, high contrast, and fast response speed. ► Color electrowetting display is manufactured by using black oil ink as an absorbing switch. ► Conventional dis-azo black dyes possess poor solubility in linear alkanes. ► Previous researches have focused on designing of electrowetting devices. ► These dis-azo black dyes were resulted in having high solubility and neutral hue. - Abstract: This study was to design and synthesize a series of dis-azo dyes derived from p-n-alkyl aniline by introducing different alkyl group resulted in having high solubility in linear alkanes solvents, even absorption intensity of visible wavelengths. Results indicated that elementary properties of black oil ink were (1) non-polar; (2) low viscosity (<3.0 cps); (3) specified surface tension (<30 mN/m); (4) intensity of visible absorption uniformly covering 400–800 nm; (5) FoM equal to 100–1000; (6) hue close to standard black (L = 0, a = 0, b = 0). We can conclude that dis-azo black dyes fulfills elementary conditions of colored oil ink for electrowetting display.

  1. Chlorine disinfection of dye wastewater: implications for a commercial azo dye mixture.

    Science.gov (United States)

    Vacchi, Francine Inforçato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre; Ormond, Alexandra B; Freeman, Harold S; Zocolo, Guilherme Julião; Zanoni, Maria Valnice Boldrin; Umbuzeiro, Gisela

    2013-01-01

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. PMID:23178834

  2. Detoxification of azo dyes in the context of environmental processes.

    Science.gov (United States)

    Rawat, Deepak; Mishra, Vandana; Sharma, Radhey Shyam

    2016-07-01

    Azo dyes account for >70% of the global industrial demand (∼9 million tons). Owing to their genotoxic/carcinogenic potential, the annual disposal of ∼4,500,000 tons of dyes and/or degraded products is an environmental and socio-economic concern. In comparison to physico-chemical methods, microbe-mediated dye degradation is considered to be low-input, cost-effective and environmentally-safe. However, under different environmental conditions, interactions of chemically diverse dyes with metabolically diverse microbes produce metabolites of varying toxicity. In addition, majority of studies on microbial dye-degradation focus on decolorization with least attention towards detoxification. Therefore, the environmental significance of microbial dye detoxification research of past >3 decades is critically evaluated with reference to dye structure and the possible influence of microbial interactions in different environments. In the absence of ecosystem-based studies, the results of laboratory-based studies on dye degradation, metabolite production and their genotoxic impact on model organisms are used to predict the possible fate and consequences of azo dyes/metabolites in the environment. In such studies, the predominance of fewer numbers of toxicological assays that too at lower levels of biological organization (molecular/cellular/organismic) suggests its limited ecological significance. Based on critical evaluation of these studies the recommendations on inclusion of multilevel approach (assessment at multiple levels of biological organization), multispecies microcosm approach and native species approach in conjunction with identification of dye metabolites have been made for future studies. Such studies will bridge the gap between the fundamental knowledge on dye-microbe-environment interactions and its application to combat dye-induced environmental toxicity. Thus an environmental perspective on dye toxicity in the background of dye structure and effects of

  3. Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

    Energy Technology Data Exchange (ETDEWEB)

    Vacchi, Francine Inforcato; Albuquerque, Anjaina Fernandes; Vendemiatti, Josiane Aparecida; Morales, Daniel Alexandre [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil); Ormond, Alexandra B.; Freeman, Harold S. [Department of Textile Engineering, Chemistry, and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Zocolo, Guilherme Juliao; Zanoni, Maria Valnice Boldrin [Departamento de Quimica Analitica, Universidade Estadual Paulista Julio de Mesquita Filho, Instituto de Quimica de Araraquara, Araraquara, SP 14801-970 (Brazil); Umbuzeiro, Gisela, E-mail: giselau@ft.unicamp.br [Faculdade de Tecnologia, Universidade Estadual de Campinas, Limeira, SP, 13484-332 (Brazil)

    2013-01-01

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC-ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: Black-Right-Pointing-Pointer Aqueous solutions of Disperse Red 1 were treated with chlorine. Black-Right-Pointing-Pointer The chlorination products of Disperse Red 1 were identified using LC-ESI-MS/MS. Black-Right-Pointing-Pointer Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. Black-Right-Pointing-Pointer The chlorinated dye was more mutagenic

  4. Chlorine disinfection of dye wastewater: Implications for a commercial azo dye mixture

    International Nuclear Information System (INIS)

    Azo dyes, the most widely used family of synthetic dyes, are often employed as colorants in areas such as textiles, plastics, foods/drugs/cosmetics, and electronics. Following their use in industrial applications, azo dyes have been found in effluents and various receiving waters. Chemical treatment of effluents containing azo dyes includes disinfection using chlorine, which can generate compounds of varying eco/genotoxicity. Among the widely known commercial azo dyes for synthetic fibers is C.I. Disperse Red 1. While this dye is known to exist as a complex mixture, reports of eco/genotoxicity involve the purified form. Bearing in mind the potential for adverse synergistic effects arising from exposures to chemical mixtures, the aim of the present study was to characterize the components of commercial Disperse Red 1 and its chlorine-mediated decoloration products and to evaluate their ecotoxicity and mutagenicity. In conducting the present study, Disperse Red 1 was treated with chlorine gas, and the solution obtained was analyzed with the aid of LC–ESI-MS/MS to identify the components present, and then evaluated for ecotoxicity and mutagenicity, using Daphnia similis and Salmonella/microsome assays, respectively. The results of this study indicated that chlorination of Disperse Red 1 produced four chlorinated aromatic compounds as the main products and that the degradation products were more ecotoxic than the parent dye. These results suggest that a disinfection process using chlorine should be avoided for effluents containing hydrophobic azo dyes such commercial Disperse Red 1. -- Highlights: ► Aqueous solutions of Disperse Red 1 were treated with chlorine. ► The chlorination products of Disperse Red 1 were identified using LC–ESI-MS/MS. ► Daphnia and Salmonella/microsome were employed for eco/genotoxicity testing. ► The chlorinated dye was more mutagenic than the dye itself. ► Chlorination should be avoided in effluents containing azo-dyes.

  5. Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

    International Nuclear Information System (INIS)

    This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of azo dyes (i.e., naphthol type azo dyes - Reactive Black 5 (RB 5), Reactive Blue 171 (RB 171), Reactive Green 19 (RG19), Reactive Red 198 (RR198), Reactive Red 141 (RR141) and non-naphthol type azo dyes - Direct Yellow 86 (DY86), Reactive Yellow 84 (RY84)) affected color removal capability of Aeromonas hydrophila. Generally speaking, the decolorization rate of naphthol type azo dye with hydroxyl group at ortho to azo bond was faster than that of non-naphthol type azo dye without hydroxyl group, except of RG19. The azo dyes with electron-withdrawing groups (e.g., sulfo group in RR198, RB5 and RR141) would be easier to be decolorized than the azo dyes with the electron-releasing groups (e.g., -NH-triazine in RB171 and RG19). In addition, the azo dyes containing more electron-withdrawing groups (e.g., RR198, RB5 and RR141) showed significantly faster rate of decolorization. The azo dyes with electron-withdrawing groups (e.g., sulfo group) at para and ortho to azo bond (e.g., RR198, RB5 and RR141) could be more preferred for color removal than those at meta (e.g., DY86 and RY84). The former azo dyes with para and ortho sulfo group provided more effective resonance effects to withdraw electrons from azo bond, causing azo dyes to be highly electrophilic for faster rates of reductive biodecolorization. However, since the ortho substituent caused steric hindrance near azo linkage(s), azo dyes with para substituent could be more favorable (e.g., SO2(CH2)2SO4- in RR198 and RB5) than those with ortho substituent (e.g., sulfo group at RR141) for decolorization. Thus, the ranking of the position for the electron-withdrawing substituent in azo dyes to escalate decolorization was para > ortho > meta. This study suggested that both the positions of substituents on the aromatic ring and the electronic characteristics of substituents in azo dyes all

  6. Understanding effects of chemical structure on azo dye decolorization characteristics by Aeromonas hydrophila

    Energy Technology Data Exchange (ETDEWEB)

    Hsueh, Chung-Chuan [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Chen, Bor-Yann, E-mail: bychen@niu.edu.tw [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China); Yen, Chia-Yi [Department of Chemical and Materials Engineering, National I-Lan University, I-Lan 260, Taiwan (China)

    2009-08-15

    This novel comparative study tended to disclose how the molecular structures present in seven azo dyes including two types of azo dyes (i.e., naphthol type azo dyes - Reactive Black 5 (RB 5), Reactive Blue 171 (RB 171), Reactive Green 19 (RG19), Reactive Red 198 (RR198), Reactive Red 141 (RR141) and non-naphthol type azo dyes - Direct Yellow 86 (DY86), Reactive Yellow 84 (RY84)) affected color removal capability of Aeromonas hydrophila. Generally speaking, the decolorization rate of naphthol type azo dye with hydroxyl group at ortho to azo bond was faster than that of non-naphthol type azo dye without hydroxyl group, except of RG19. The azo dyes with electron-withdrawing groups (e.g., sulfo group in RR198, RB5 and RR141) would be easier to be decolorized than the azo dyes with the electron-releasing groups (e.g., -NH-triazine in RB171 and RG19). In addition, the azo dyes containing more electron-withdrawing groups (e.g., RR198, RB5 and RR141) showed significantly faster rate of decolorization. The azo dyes with electron-withdrawing groups (e.g., sulfo group) at para and ortho to azo bond (e.g., RR198, RB5 and RR141) could be more preferred for color removal than those at meta (e.g., DY86 and RY84). The former azo dyes with para and ortho sulfo group provided more effective resonance effects to withdraw electrons from azo bond, causing azo dyes to be highly electrophilic for faster rates of reductive biodecolorization. However, since the ortho substituent caused steric hindrance near azo linkage(s), azo dyes with para substituent could be more favorable (e.g., SO{sub 2}(CH{sub 2}){sub 2}SO{sub 4}{sup -} in RR198 and RB5) than those with ortho substituent (e.g., sulfo group at RR141) for decolorization. Thus, the ranking of the position for the electron-withdrawing substituent in azo dyes to escalate decolorization was para > ortho > meta. This study suggested that both the positions of substituents on the aromatic ring and the electronic characteristics of

  7. Decomposed characteristic of azo dyes by ozonization with ultrasonic enhancement

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Azo dyes have been used in many industries (textile mill, printing and dyeing mill, paper and pulp mill) and have caused great environmental pollution due to complicated constitution and high chemical stability. The construction of azo dyes can be destroyed by ozonization, but not thoroughly when the ozone dosage is controlled to a certain extent and the operating cost is higher. Ozonization decomposed ability with ultrasonic enhancement on azo dyes has been demonstrated in the study. The conclusion derived from this investigation may be summarized as follows: (1) The decoloration rate of arsenazoⅠsolutions during sonozone treatment is more rapid than the rate obtained with ozone alone because the complicated constitution has been destroyed by the O free radical from ozone decomposition. (2) The destructing pathway of arsenazoⅠby ozone with ultrasound is identical with that of by ozone alone: the breakdown of -N== N- bonds, the conversion of benzene ring to carboxylic acid, and -HSO3 bonds to H2SO4. So, pH value of the arsenazo Ⅰ solution continuously drops down to 3.2.

  8. Synthesis, characterization and dyeing assessment of novel acid azo dyes and mordent acid azo dyes based on 2-hydroxy-4-methoxybenzophenone on wool and silk fabrics

    Directory of Open Access Journals (Sweden)

    DHIRUBHAI J. DESAI

    2010-05-01

    Full Text Available Novel acid mono azo and mordent acid mono azo dyes were synthesised by the coupling of diazonium salt solution of different aromatic amines with 2-hydroxy-4-methoxybenzophenone. The resulting dyes were characterized by spectral techniques, i.e., elemental analysis, IR, 1H-NMR and UV–visible spectroscopy. The dyeing performance of all the dyes was evaluated on wool and silk fabrics. The dyeing of chrome pre-treated wool and silk fabrics showed better hues on mordented fabrics. Dyeing of wool and silk fabrics resulted in pinkish blue to red shades with very good depth and levelness. The dyed fabrics showed excellent to very good light, washing, perspiration, sublimation and rubbing fastness. The results of antibacterial studies of chrome pre-treated fabrics revealed that the toxicity of mordented dyes against Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus subtilis bacteria was fairly good.

  9. The contribution of biotic and abiotic processes during azo dye reduction in anaerobic sludge

    NARCIS (Netherlands)

    Zee, van der F.P.; Bisschops, I.A.E.; Blanchard, V.G.; Bouwman, R.H.M.; Lettinga, G.; Field, J.A.

    2003-01-01

    Azo dye reduction results from a combination of biotic and abiotic processes during the anaerobic treatment of dye containing effluents. Biotic processes are due to enzymatic reactions whereas the chemical reaction is due to sulfide. In this research, the relative impact of the different azo dye red

  10. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    OpenAIRE

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16...

  11. Isolation and screening of azo dye decolorizing bacterial isolates from dye-contaminated textile wastewater

    Directory of Open Access Journals (Sweden)

    Shahid Mahmood

    2011-04-01

    Full Text Available Azo dyes are released into wastewater streams without any pretreatment and pollute water and soilenvironments. To prevent contamination of our vulnerable resources, removal of these dye pollutants is of greatimportance. For this purpose, wastewater samples were collected from dye-contaminated sites of Faisalabad. About200 bacterial isolates were isolated through enrichment and then tested for their potential to remove RemazolBlack-B azo dye in liquid medium. Five bacterial isolates capable of degrading Remazol Black-B azo dye efficientlywere screened through experimentation on modified mineral salt medium. Isolate SS1 (collected from wastewater ofSupreme Textile Industry was able to completely remove the Remazol Black-B dye from the liquid medium in 18 h.Further, the isolate showed the best performance at the dye concentration of 100 mg L-1 medium (pH 7 and attemperature 35oC. Similarly, yeast extract proved to be the best carbon source for decolorization purpose. Theresults imply that the isolate SS1 could be used for the removal of the reactive dyes from textile effluents.

  12. Dye-sensitized solar cell based on AZO/Ag/AZO multilayer transparent conductive oxide film

    International Nuclear Information System (INIS)

    Highlights: ► AZO/Ag/AZO (AAA) multilayer was used for working electrode of DSSC cell. ► The 100 nm-thick Nb-doped TiO2 layer showed a good blocking effect. ► The DSSC cell by AAA TCO material showed the highest efficiency of about 3.25%. -- Abstract: Niobium-doped TiO2 blocking layer and Al-doped ZnO (AZO)/Ag/AZO (AAA) TCO layers were grown onto glass substrate using pulsed laser deposition (PLD) and direct current (dc)/radio-frequency (rf) sputtering at room temperature, respectively for dye-sensitized solar cell (DSSC) applications. The 100 nm-thick NTO layer showed a blocking effect for the oxygen diffusion into AAA layer and for the recombination of the electrons. The DSSC cell composed of the NTO (100 nm)/AAA (400 nm) showed the highest photo-electrical efficiency of about 3.25%. An insertion of aluminum foil between serrated clip and AAA (100 nm) TCO improved a photo-conversion efficiency of the DSSC

  13. Simultaneous chromate reduction and azo dye decolourization by Brevibacterium casei: Azo dye as electron donor for chromate reduction

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Tsz Wai; Cai Qinhong [Department of Biology, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Wong, Chong-Kim [Department of Biology, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Environmental Science Programme, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Chow, Alex T. [Department of Biosystems Engineering, Clemson University, SC 29634 (United States); Department of Forestry and Natural Resources, Clemson University, SC 29634 (United States); Wong, Po-Keung, E-mail: pkwong@cuhk.edu.hk [Department of Biology, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong); Environmental Science Programme, Chinese University of Hong Kong, Shatin, N.T. (Hong Kong)

    2010-10-15

    Chromate [Cr(VI)] and azo dyes are common pollutants which may co-exist in some industrial effluents. Hence studies of biological treatment of industrial wastewater should include investigation of the co-removal of these two pollutants. Brevibacterium casei, which can reduce Cr(VI) in the presence of the azo dye Acid Orange 7 (AO7) under nutrient-limiting condition, was isolated from a sewage sludge sample of a dyeing factory. Response surface methodology, which is commonly used to optimize growth conditions for food microorganisms to maximize product(s) yield, was used to determine the optimal conditions for chromate reduction and dye decolourization by B. casei. The optimal conditions were 0.24 g/L glucose, 3.0 g/L (NH{sub 4}){sub 2}SO{sub 4} and 0.2 g/L peptone at pH 7 and 35 deg. C. The predicted maximum chromate reduction efficiencies and dye decolourization were 83.4 {+-} 0.6 and 40.7 {+-} 1.7%, respectively. A new mechanism was proposed for chromate reduction coupling with AO7 decolourization by B. casei. Under nutrient-limiting condition, AO7 was used as an e{sup -} donor by the reduction enzyme(s) of B. casei for the reduction of Cr(VI). The resulted Cr(III) then complexed with the oxidized AO7 to form a purple coloured intermediate.

  14. Simultaneous chromate reduction and azo dye decolourization by Brevibacterium casei: Azo dye as electron donor for chromate reduction

    International Nuclear Information System (INIS)

    Chromate [Cr(VI)] and azo dyes are common pollutants which may co-exist in some industrial effluents. Hence studies of biological treatment of industrial wastewater should include investigation of the co-removal of these two pollutants. Brevibacterium casei, which can reduce Cr(VI) in the presence of the azo dye Acid Orange 7 (AO7) under nutrient-limiting condition, was isolated from a sewage sludge sample of a dyeing factory. Response surface methodology, which is commonly used to optimize growth conditions for food microorganisms to maximize product(s) yield, was used to determine the optimal conditions for chromate reduction and dye decolourization by B. casei. The optimal conditions were 0.24 g/L glucose, 3.0 g/L (NH4)2SO4 and 0.2 g/L peptone at pH 7 and 35 deg. C. The predicted maximum chromate reduction efficiencies and dye decolourization were 83.4 ± 0.6 and 40.7 ± 1.7%, respectively. A new mechanism was proposed for chromate reduction coupling with AO7 decolourization by B. casei. Under nutrient-limiting condition, AO7 was used as an e- donor by the reduction enzyme(s) of B. casei for the reduction of Cr(VI). The resulted Cr(III) then complexed with the oxidized AO7 to form a purple coloured intermediate.

  15. Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan

    Directory of Open Access Journals (Sweden)

    Ghorban Asgari

    2013-01-01

    Full Text Available We introduce a new adsorbent, bimetallic chitosan particle (BCP that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1 mg/L of BCP is 10 min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6 mg/g. The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1 mg/L, within a short reaction time of 20 min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively.

  16. The pH-sensitive properties of azo dyes in aqueous environment

    OpenAIRE

    Meyer, Thierry; Hemelsoet, Karen; Van der Schueren, Lien; PAUWELS, EWALD; De Clerck, Karen; Van Speybroeck, Veronique

    2012-01-01

    Azo dyes consist of a double nitrogen-nitrogen bond connected to two aromatic moieties, creating a large conjugated pi-system. A relatively simple synthesis and large variety of colours have made azo dyes the most abundant class of colourants. The dye studied in this research, ethyl orange (EO), is a prototypical example of a halochromic (pH-sensitive) azo dye. Halochromic dyes have already proven useful for application in textile sensors since the colour change of such sensors is easy to per...

  17. Texture-modified activated carbons as catalysts in biodecolourisation of azo dyes

    OpenAIRE

    Mezohegyi, Gergo; Gonçalves, Filomena; Órfao, José J.M.; Bengoa, Christophe José; Stüber, Frank Erich; Font Capafons, Josep; Fortuny Sanromá, Agustín; Fabregat Llangotera, Azael

    2009-01-01

    Considerable attention has been focused on the reduction of azo dyes discharged from dyeing, textile and other industries since some of them or their metabolites may cause toxicity. The efficient treatment of these effluents at industrual scale presents many difficulties, particularly at high dye concentrations and at low energy consumptions. Anaerobic biodecolourisation seems to be the most economic and environmentally friendly method for azo dye wastewater treatment. In a rec...

  18. Biological Treatment of a Synthetic Dye Water and an Industrial Textile Wastewater Containing Azo Dye Compounds

    OpenAIRE

    Wallace, Trevor Haig

    2001-01-01

    In this research, the ability of anaerobic and aerobic biological sludges to reduce and stabilize azo dye compounds was studied. Synthetic dye solutions and an industrial textile wastewater were both treated using anaerobic and aerobic biomass, separately and in sequential step-treatment processes. The primary objective was to reduce the wastewater color to an intensity that complies with the Virginia Pollutant Discharge Elimination System (VPDES) permit level. This level is set at 300 Ame...

  19. Azo dye biodecolorization enhanced by Echinodontium taxodii cultured with lignin.

    Directory of Open Access Journals (Sweden)

    Yuling Han

    Full Text Available Lignocellulose facilitates the fungal oxidization of recalcitrant organic pollutants through the extracellular ligninolytic enzymes induced by lignin in wood or other plant tissues. However, available information on this phenomenon is insufficient. Free radical chain reactions during lignin metabolism are important in xenobiotic removal. Thus, the effect of lignin on azo dye decolorization in vivo by Echinodontium taxodii was evaluated. In the presence of lignin, optimum decolorization percentages for Remazol Brilliant Violet 5R, Direct Red 5B, Direct Black 38, and Direct Black 22 were 91.75% (control, 65.96%, 76.89% (control, 43.78%, 43.44% (control, 17.02%, and 44.75% (control, 12.16%, respectively, in the submerged cultures. Laccase was the most important enzyme during biodecolorization. Aside from the stimulating of laccase activity, lignin might be degraded by E. taxodii, and then these degraded low-molecular-weight metabolites could act as redox mediators promoting decolorization of azo dyes. The relationship between laccase and lignin degradation was investigated through decolorization tests in vitro with purified enzyme and dozens of aromatics, which can be derivatives of lignin and can function as laccase mediators or inducers. Dyes were decolorized at triple or even higher rates in certain laccase-aromatic systems at chemical concentrations as low as 10 µM.

  20. Azo dye biodecolorization enhanced by Echinodontium taxodii cultured with lignin.

    Science.gov (United States)

    Han, Yuling; Shi, Lili; Meng, Jing; Yu, Hongbo; Zhang, Xiaoyu

    2014-01-01

    Lignocellulose facilitates the fungal oxidization of recalcitrant organic pollutants through the extracellular ligninolytic enzymes induced by lignin in wood or other plant tissues. However, available information on this phenomenon is insufficient. Free radical chain reactions during lignin metabolism are important in xenobiotic removal. Thus, the effect of lignin on azo dye decolorization in vivo by Echinodontium taxodii was evaluated. In the presence of lignin, optimum decolorization percentages for Remazol Brilliant Violet 5R, Direct Red 5B, Direct Black 38, and Direct Black 22 were 91.75% (control, 65.96%), 76.89% (control, 43.78%), 43.44% (control, 17.02%), and 44.75% (control, 12.16%), respectively, in the submerged cultures. Laccase was the most important enzyme during biodecolorization. Aside from the stimulating of laccase activity, lignin might be degraded by E. taxodii, and then these degraded low-molecular-weight metabolites could act as redox mediators promoting decolorization of azo dyes. The relationship between laccase and lignin degradation was investigated through decolorization tests in vitro with purified enzyme and dozens of aromatics, which can be derivatives of lignin and can function as laccase mediators or inducers. Dyes were decolorized at triple or even higher rates in certain laccase-aromatic systems at chemical concentrations as low as 10 µM. PMID:25285777

  1. Synthesis, characterization and application of new azo dyes derived from uracil for polyester fibre dyeing

    Science.gov (United States)

    Yazdanbakhsh, Mohamad-reza; Abbasnia, Masoumeh; Sheykhan, Mehdi; Ma'mani, Leila

    2010-08-01

    Some novel uracil derived azo compounds were synthesized by diazotization of substituted aromatic amines, amidine- and guanidine-like amines such as 2-aminopyridine and 2-aminopyrimidine, ortho-hydroxy aniline and ortho-hydroxy naphthyl amines and coupling reaction with 6-amino-1,3-dimethyluracil. Structures of the dyes were fully characterized by spectroscopic techniques (UV, 1H NMR, 13C NMR, CHN and IR). The dyes were applied to polyester, affording orange-yellow shades and the wash fastness of the dyeings was excellent.

  2. Enzymatic reduction and oxidation of fibre-bound azo-dyes

    OpenAIRE

    Pricelius, S.; Held, C; Sollner, S.; Deller, S.; Murkovic, M.; Ullrich, R; Hofrichter, M.; Paulo, Artur Cavaco; Macheroux, P.; Guebitz, G. M.

    2007-01-01

    A new customer and environmental friendly method of hair bound dye decolouration was developed. Biotransformation of the azo-dyes Flame Orange and Ruby Red was studied using different oxidoreductases. The pathways of azo dye conversion by these enzymes were investigated and the intermediates and metabolites were identified and characterised using UV–vis spectroscopy, high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Laccase from Pycnoporus cinnabarinus, manganese perox...

  3. Photoluminescence analysis of self induced planer alignment in azo dye dispersed nematic liquid crystal complex

    International Nuclear Information System (INIS)

    We have developed azo dye doped nematic liquid crystal complex for advanced photonic liquid crystal display technology aspects. Disperse orange azo dye self introduced planer alignment in the nematic liquid crystal without any surface anchoring treatment. Planer alignment was characterized by optical polarizing microscopy. The electro-optical switching response of dye disperse planer aligned nematic cell was investigated as a function of applied voltage with the help of photoluminescence spectrophotometer for the tuning of photoluminescence contrast

  4. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    OpenAIRE

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reac-tive Black 5 (RB 5), Reactive Orange 1...

  5. Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

    OpenAIRE

    Naeem Ali; Abdul Hameed; Safia Ahmed

    2010-01-01

    The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1) was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR) 151(di-azo) as compared to Orange (Or) II (mono-azo). With an exception of Aspergillus tereus SA3, all the...

  6. REDUCTION OF AZO DYES WITH ZERO-VALENT IRON. (R827117)

    Science.gov (United States)

    The reduction of azo dyes by zero-valent iron metal (Fe0) at pH 7.0 in 10 mM HEPES buffer was studied in aqueous, anaerobic batch systems. Orange II was reduced by cleavage of the azo linkage, as evidenced by the production of sulfanilic acid (a substituted ani...

  7. Synthesis and Characterization of Azo Dye Para Red and New Derivatives

    OpenAIRE

    Al-Rubaie, L. Abd-Alredha R.; R. Jameel Mhessn

    2012-01-01

    Azo dyes para red was synthesized. The products were characterized by FTIR and UV-Visible spectrophotometers. The antibacterial activities of the compounds were studied using gram positive and gram negative microorganism.

  8. Azo dye decolorization by Shewanella aquimarina under saline conditions.

    Science.gov (United States)

    Meng, Xianming; Liu, Guangfei; Zhou, Jiti; Shiang Fu, Q; Wang, Guanghui

    2012-06-01

    Decolorization of azo dyes under saline conditions was studied with Shewanella aquimarina, which demonstrated good growth at up to 7% NaCl. No inhibition on acid red 27 (AR27) decolorization was caused by 1-3% NaCl. Additionally, 14.5% AR27 (0.2mM) could still be removed in 12h in the presence of 10% NaCl. The relationship between specific decolorization rate and AR27 concentration followed Michaelis-Menten kinetics (K(m)=0.34 mM, V(max)=6.44 μmol mg cell(-1) h(-1)). Lactate and formate were efficient electron donors for AR27 decolorization. The initial decolorization rate was in direct proportion to biomass concentration (0.18-0.72 g l(-1)). Compared to NaCl, slighter inhibitive effects were found with Na(2)SO(4) whereas more severe inhibition was caused by NaNO(3). Lower NaCl concentration stimulated azoreductase, laccase and NADH-DCIP reductase activities of cell extracts. AR27 decolorization products were found to be aromatic amines, which were less phytotoxic than the untreated dye. PMID:22449986

  9. 'Naturalization' of textile disperse dyes through glycoconjugation: the case of a bis(2-hydroxyethyl) group containing azo dye.

    Science.gov (United States)

    Bianchini, Roberto; Catelani, Giorgio; Cecconi, Riccardo; D'Andrea, Felicia; Frino, Elena; Isaad, Jalal; Rolla, Massimo

    2008-08-11

    A family of five strictly related glycoconjugated azo dyes (GADs), characterized by the presence of the same chromophore and a variable number (1-4) of deprotected hexose units, has been prepared by employing succinate bridges for connecting the azo dye and the sugar portions. The modulation of the hydrophilic portion determines the appreciable changes in the water solubility of GADs. In all the cases, however, hydrophobic fibres (polyester) were homogeneously dyed with GADs at temperatures lower than that used for original azo dyes, at atmospheric pressure, and avoiding the use of surfactants. Furthermore, GADs show an interesting multipurpose character leading to dyeing well also the natural fibres as, for instance, wool. The presence of a variable number of hexose units in the different GADs determines some changes in the colour intensity of dyed fabrics, but in all the cases an appreciable rubbing and water fastness were maintained. PMID:18336806

  10. Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

    Directory of Open Access Journals (Sweden)

    Naeem Ali

    2010-12-01

    Full Text Available The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1 was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR 151(di-azo as compared to Orange (Or II (mono-azo. With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67% and Alternaria spp. SA4 (57% in AR 151, while Penicillium spp. (34 and 33 % in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased (% in; AR 151 (255 with Penicillium spp., Or II with A. flavus SA2 (112 and Alternaria spp. (111. The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal with formation of their products (α. naphthol, sulphalinic acid and aniline furthermore revealed that dyes (specifically azo were actually biodegraded.

  11. Comparison of decolorization of reactive azo dyes by microorganisms isolated from various sources

    Institute of Scientific and Technical Information of China (English)

    S.Padamavathy; S.Sandhya; K.Swaminathan; Y.V.Subrahmanyam; S.N.Kaul

    2003-01-01

    Azo dyes are among the oldest man-made chemicals and they are still widely used in the textile, printing and the food industries. About 10%-15% of the total dyes used in the industry is released into the environment during the manufacturing and usage. Some dyes and some of their N-substituted aromatic bio-transformation products are toxic and/or carcinogenic and therefore these dyes are considered to be environmental pollutants and health hazards. These azo dyes are degraded by physico-chemical and biological methods. Of these, biological methods are considered to be the most economical and efficient. In this work, attempts were made to degrade these dyes aerobically. The organisms which were efficient in degrading the following azo dyes-Red RB, Remazol Red, Remazol Blue, Remazol Violet, Remazol Yellow, Golden Yellow, Remazol Orange, Remazol Black- were isolated from three different sources viz., wastewater treatment plant, paper mill effluent treatment plant and tannery wastewater treatment plant. The efficiency of azo dye degradation by mixed cultures from each source was analyzed. It was found that mixed cultures from tannery treatment plant worked efficiently in decolorizing Remazol Red, Remazol Orange, Remazol Blue and Remazol Violet, while mixed cultures from the paper mill effluent worked efficiently in decolorizing Red RB, Golden Yellow and Remazol Yellow. The mixed cultures from wastewater treatment plant efficiently decolorized Remazol Black.

  12. Comparative studies of fungal degradation of single or mixed bioaccessible reactive azo dyes

    OpenAIRE

    Martins, M. Adosinda M.; Lima, Nelson; Silvestre, Armando J. D.; Queiroz, Maria João R. P.

    2003-01-01

    A screening using several fungi (Phanerochaete chrysosporium, Pleurotus ostreatus, Trametes versicolor and Aureobasidium pullulans) was performed on the degradation of syringol derivatives of azo dyes possessing either carboxylic or sulphonic groups, under optimized conditions previously established by us. T. versicolor showed the best biodegradation performance and its potential was confirmed by the degradation of differently substituted fungal bioaccessible dyes. Enzymatic assay...

  13. ENVIRONMENTAL APPLICATIONS OF THERMOSPRAY LCMS: QUALITATIVE ANALYSIS OF SULFONATED AZO DYES

    Science.gov (United States)

    Thermospray mass spectra (TSMS) has been used to obtain mass spectra of several di- and tetra- sulfonated azo dyes. Commercial dye preparations were dissolved in various mobile phases and injected into the TSMS system. Mobile phases investigated included pure water and varying co...

  14. Ozonation of azo dyes (Orange II and Acid Red 27) in saline media

    International Nuclear Information System (INIS)

    Ozonation of two azo dyes was investigated in a monitored bench scale bubble column reactor (8.5-L), varying liquid media salt content (0, 1, 40 and 100 g L-1, NaCl). In experiments with Orange II pH was varied (5, 7.5 and 9) but ozonation of Acid Red 27 was performed at pH 7.5. Ozone self-decomposition rate-constant increased with salt concentration. Color removal was very effective and fast achieved under all experimental conditions. For the two azo dyes tested, more than 98% of color intensity was removed in 30-min ozonation assays. However, only partial mineralization of azo dyes (45%-Orange II; 20%-Acid Red 27) was attained in such experiments. The degree of mineralization (TOC removal) was negatively affected by salt concentration. Biodegradation assays conducted by respirometry revealed the inhibitory effect of dye degradation products formed during ozonation.

  15. Effects of polarization conditions on molecular orientation in azo-dye compound film

    International Nuclear Information System (INIS)

    In order to investigate the influence of polarization conditions on azo-dye molecular orientation in films, azo-dye polymer films of guest-host system were prepared by spin-coating method. The average alignment factor of azo-dye molecules in films were investigated by UV-Vis spectra measured before and after corona poling, as well as second harmonic generation at different corona poling conditions. The experimental results show that the average alignment factor of azo-dye films becomes bigger, and second harmonic intensity first increases and then decreases with the increasing of poling temperature. The closer the poling temperature is to the polymer's glass transition temperature, the more likely the molecules are orientated. However, PMMA will fall into a state of viscosity at too high temperature. A part of azo-dye molecules will evaporate easily at high temperature, making the second harmonic intensity decline and the average alignment factor increase. As the film thickness increases, the inhomogeneity of electric field distribution in films increases, which is caused by point-plane corona discharges, the polarization efficiency reduces, and therefore the average alignment factor decreases and the second harmonic intensity first increases and then decreases. (authors)

  16. RAPID DEGRADATION OF AZO DYES USING NANO-SCALE ZERO VALENT IRON

    Directory of Open Access Journals (Sweden)

    Nabila Rahman

    2014-01-01

    Full Text Available In the present study, nano-scale Zero Valent Iron (NZVI was synthesized in ethanol medium by the method of ferric iron reduction using sodium borohydride as a reducing agent under atmospheric conditions. The obtained iron nanoparticles are mainly in zero valent oxidation state and remain without significant oxidation for hours. A systematic characterization of NZVI was performed using XRD, SEM and TEM studies. The obtained iron nanoparticles consist of a zero valent core surrounding a rest oxide shell. The diameter of iron nanoparticles was predominantly within the range 20-110 nm. Refractory azo-dye compounds used in the textile industry are commonly detected in many industrial waste water. In this study the removal efficiency of three azo dyes, namely, methyl orange, sunset yellow and acid blue a, with laboratory synthesized NZVI particles in relation to the NZVI dosage, dye concentration and pH was determined. Increasing the dose of NZVI particles enhanced the decolonization of the dyes. The degradation decreased with increasing solution pH and concentration of dyes. These findings demonstrated the fast removal of azo dye compounds with NZVI and the advantage of the synthesized NZVI particles to treat azo dye contaminated wastewater.

  17. Synthesis, Structural Evaluation and Applications of Vinylsulfone Based Azo Reactive Dyes

    International Nuclear Information System (INIS)

    In this work, three novel vinylsulfone based azo reactive dyes were successfully synthesized by successive condensations, diazotization and coupling reaction steps using reactive acids i.e. H-acid, J-acid and gamma-acid respectively. Synthesized dyes were applied with 3% dye (stock) solutions on the mill scoured; bleached and desized cotton fabric by exhaust method of dyeing. UV- visible absorption spectroscopic properties of the azo dyes were recorded among wavelength range (400-800 nm), prepared in double distilled water as lambda/sub max/. The prepared dyes were purified with physico- chemical method and characterized by means of different analytical techniques i.e. FT-IR and ESI-MS-MS to evaluate their chemical structures and molecular mass. (author)

  18. Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified β-Cyclodextrin Polymer

    OpenAIRE

    Bhekie B. Mamba; Phendukani Ncube; Krause, Rui W

    2011-01-01

    A water soluble azo dye modified β-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs) of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified β-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2...

  19. Mineralization of sulfonated azo dyes and sulfanilic acid by Phanerochaete chrysosporium and Streptomyces chromofuscus.

    OpenAIRE

    Paszczynski, A; Pasti-Grigsby, M B; Goszczynski, S; Crawford, R L; Crawford, D. L.

    1992-01-01

    Five 14C-radiolabeled azo dyes and sulfanilic acid were synthesized and used to examine the relationship between dye substitution patterns and biodegradability (mineralization to CO2) by a white-rot fungus and an actinomycete. 4-Amino-[U-14C]benzenesulfonic acid and 4-(3-sulfo-4-aminophenylazo)-[U-14C]benzenesulfonic acid were used as representative compounds having sulfo groups or both sulfo and azo groups. Such compounds are not known to be present in the biosphere as natural products. The ...

  20. Decolorization of Textile Dyes and Degradation of Mono-Azo Dye Amaranth by Acinetobacter calcoaceticus NCIM 2890

    OpenAIRE

    Ghodake, Gajanan; Jadhav, Umesh; Tamboli, Dhawal; Kagalkar, Anuradha; Govindwar, Sanjay

    2011-01-01

    Acinetobacter calcoaceticus NCIM 2890 (A. caloaceticus) was found to decolorize 20 different textile dyes of various classes. Decolorization of an azo dye amaranth was observed effectively (91%) at static anoxic condition, whereas agitated culture grew well but showed less decolorization (68%) within 48 h of incubation. Induction of intracellular and extracellular lignin peroxidase, intracellular laccase, dichlorophenol indophenol (DCIP) reductase and riboflavin reductase represented their in...

  1. Removal of selected azo dyes from textile wastewater by chemical coagulation/flocculation: implication of the dye destabilization mechanism

    OpenAIRE

    Janeczko, M.; GAYDARDZHIEV, Stoyan; Ay, P.

    2006-01-01

    The results of the coagulation/flocculation of six commercially used textile azo dyes coagulated with synthetic primary coagulants are discussed in the paper. Surface charge measurement of coagulated dye-flocs was employed to find a correlation between its sign and the level of colour removal. Additionally, flocs characterization was done with the aim to link data with surface charge and on this basis to outline the predominant mechanism of colour removal. Based on the results obtained, the e...

  2. The oxidation of acid azo dye AY 36 by a manganese oxide containing mine waste

    International Nuclear Information System (INIS)

    Highlights: ► This study looks at the oxidative breakdown of the amine containing dye acid yellow 36 by a Mn oxide containing mine waste. ► The oxidation proceeds by successive one electron transfers between the dye molecule and the Mn oxide minerals. ► The initial decolorization of the dye is rapid, but does not involve the cleavage of the azo bond. -- Abstract: The oxidative breakdown of acid azo dye acid yellow 36 (AY 36) by a Mn oxide containing mine tailings is demonstrated. The oxidation reaction is pH dependent with the rate of decolorization increasing with decreasing pH. The oxidation reaction mechanism is initiated at the amino moiety and proceeds via successive, one electron transfers from the dye to the Mn oxide minerals. The reaction pathway involves the formation of a number of colorless intermediate products, some of which hydrolyze in a Mn oxide-independent step. Decolorization of the dye is rapid and is observed before the cleavage of the azo-bond, which is a slower process. The terminal oxidation products were observed to be p-benzoquinone and 3-hydroxybenzenesulfonate. The reaction order of the initial decolorization was determined to be pseudo fractional order with respect to pH and pseudo first order with respect to dye concentration and Mn tailings’ surface area

  3. Decolorization and biodegradation of reactive sulfonated azo dyes by a newly isolated Brevibacterium sp. strain VN-15

    OpenAIRE

    Franciscon, Elisangela; Grossman, Matthew James; Paschoal, Jonas Augusto Rizzato; Felix Guillermo Reyes REYES; Durrant, Lucia Regina

    2012-01-01

    Azo dyes constitute the largest and most versatile class of synthetic dyes used in the textile, pharmaceutical, food and cosmetics industries and represent major components in wastewater from these industrial dying processes. Biological decolorization of azo dyes occurs efficiently under low oxygen to anaerobic conditions. However, this process results in the formation of toxic and carcinogenic amines that are resistant to further detoxification under low oxygen conditions. Moreover, the abil...

  4. Degradation of azo dyes by the lignin-degrading fungus Phanerochaete chrysosporium.

    OpenAIRE

    Spadaro, J T; Gold, M H; Renganathan, V

    1992-01-01

    Under nitrogen-limiting, secondary metabolic conditions, the white rot basidiomycete Phanerochaete chrysosporium extensively mineralized the specifically 14C-ring-labeled azo dyes 4-phenylazophenol, 4-phenylazo-2-methoxyphenol, Disperse Yellow 3 [2-(4'-acetamidophenylazo)-4-methylphenol], 4-phenylazoaniline, N,N-dimethyl-4-phenylazoaniline, Disperse Orange 3 [4-(4'-nitrophenylazo)-aniline], and Solvent Yellow 14 (1-phenylazo-2-naphthol). Twelve days after addition to cultures, the dyes had be...

  5. Nano-Sized Zero Valent Iron and Covalent Organic Polymer Composites for Azo Dye Remediation

    DEFF Research Database (Denmark)

    Mines, Paul D.; Byun, Jeehye; Hwang, Yuhoon;

    2014-01-01

    Having superior reductive properties and large surface areas, nanosized zero valent iron (nZVI) is ideal for the degradation of chemicals such as azo dyes and trichloroethylene (TCE). However, immobilization of nZVI is a key parameter in its effectiveness as a chemical degradation agent. In this...

  6. Cancer risk assessment of azo dyes and aromatic amines from garment and footwear

    NARCIS (Netherlands)

    Zeilmaker MJ; Kroese ED; Haperen P van; Veen MP van; Bremmer HJ; Kranen HJ van; Wouters MFA; Janus J; LBM

    1999-01-01

    A quantitative assessment was performed to estimate the cancer risk to individuals wearing garment and footwear coloured with azo dyes. Basically, the risk assessment consists of both a comparison of the (estimated) level of aromatic amines which, during the wearing of garment and footwear, enters

  7. TREATABILITY OF WATER SOLUBLE AZO DYES BY THE ACTIVATED SLUDGE PROCESS

    Science.gov (United States)

    The U.S. Environmental Protection Agency's (EPA) Office of Toxic Substances (OTS) evaluates submissions to the Premanufacture Notification process under section 5 of the Toxic Substances Control Act. Azo dyes constitute a significant portion of these submissions. OTS is concerned...

  8. DEVELOPING AZO AND FORMAZAN DYES BASED ON ENVIRONMENTAL CONSIDERATIONS: SALMONELLA MUTAGENICITY

    Science.gov (United States)

    AbstractIn previous papers, the synthesis and chemical properties of iron-complexed azo and formazan dyes were reported. In this regard, it was shown that in certain cases iron could be substituted for the traditionally used metals, chromium and cobalt, without having an adve...

  9. Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed F. Abdel-Megeed

    2013-01-01

    Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

  10. Synthesis of New Azo Dyes and Copper(II) Complexes Derived from Barbituric Acid and 4-Aminobenzoylhydrazone

    OpenAIRE

    GUP, Bülent KIRKAN and Ramazan

    2008-01-01

    Four new azo dyes, L1, L2, L3, and L4, were prepared by linking benzaldehyde p-aminobenzoylhydrazone (3) and p-hydroxybenzaldehyede p--aminobenzoylhydrazone (4) to barbituric acid and 1,3-dimethylbarbituric acid through diazo-coupling reactions. Reactions of the azo-dyes with copper chloride and bidentate ligand, 1,10-phenanthroline, produced mixed-ligand dinuclear complexes with general stoichiometry [Cu2L(phen)2]Cl2 (7, 8, 9, and 10). The structures of both azo dyes and their compl...

  11. An experimental study on relationship between hammett substituent constant and electronic absorption wavelength of some azo dyes

    OpenAIRE

    SIDIR, Yadigar GÜLSEVEN; Sidir, Isa; BERBER, Halil; Tasal, Erol

    2011-01-01

    In this study, absorption spectra of sixteen azo dyes have been recorded in various solvents. These azo dyes have substituents such as OH, SO3H, Cl, I, NO2, C2H5 and OCH3 in different positions of phenyl ring. There is a shift in ?max whose amount is dependent upon the type and position of substituent on the ring. The effects of substituent on the absorption spectra of azo dyes are interpreted by correlation of absorption maximum wavelengths (nm) with the hammett substituent parameters. Charg...

  12. Highly efficient degradation of azo dyes by palladium/hydroxyapatite/Fe3O4 nanocatalyst

    International Nuclear Information System (INIS)

    Highlights: ► Pd/HAP/Fe3O4 catalyst was fabricated for highly efficient degradation of azo dyes. ► There is no need for the addition of an adulterant or application of light irradiation. ► The catalyst is easily recovered from reaction mixture by external magnet. ► The catalyst has excellent recyclability and stability. ► A synergistic mechanism for the azo dyes degradation in Pd/HAP/Fe3O4 systems is proposed. - Abstract: Palladium/hydroxyapatite/Fe3O4 (Pd/HAP/Fe3O4) nanocatalyst was synthesized and evaluated for its catalytic activity towards the degradation of azo dyes (methyl red, methyl orange and methyl yellow) selected as test dye species. The Pd/HAP/Fe3O4 was employed as a novel catalyst that offers high catalytic activity, magnetic separateability and good stability. It was found that catalytic activity of this catalyst was significantly enhanced under acidic conditions. The degradation mechanism is proposed to be due to the reaction of Pd/HAP/Fe3O4 with dissolved oxygen with the assistance of acid to form a Pd hydroperoxide, which oxidizes azo dyes under HAP catalysis. This in turn shows the clear importance of HAP as the support for the Pd nanocatalyst. The concentrations of dyes change exponentially with time and high rate constants were obtained for the degradation of these dyes. The pseudo-first-order equation was shown to fit degradation kinetics in most cases. Therefore, the Pd/HAP/Fe3O4 nanostructures are considered as a highly efficient and promising catalyst in degradation systems and they can be effectively recovered after use.

  13. Influence of Methyl Substituents on Azo-Dye Photoalignment in Thin Films

    Science.gov (United States)

    Mikulich, V. S.; Murawski, An. A.; Muravsky, Al. A.; Agabekov, V. E.

    2016-03-01

    Photoalignment of azo dyes derived from salicylic acid in thin films (80-200 nm) was studied upon irradiation with polarized light (λmax = 457 nm). It is shown that different trends of molecular reorientation, i.e., in the layer plane or orthogonal to it, are observed depending on the position of the methyl substituent in the dye structure. A new distribution parameter Z that allows the portion of molecules reoriented in the layer plane during exposure to be determined is introduced. The novel azo dye potassium 3,7-bis[1-(4-hydroxy-3-carboxylate)phenylazo]-5,5'-dioxodibenzothiophene was synthesized. Its molecules are photoaligned in the layer plane upon irradiation with polarized light.

  14. Reduction of azo dyes by flavin reductase from Citrobacter freundii A1

    Directory of Open Access Journals (Sweden)

    Mohd Firdaus Abdul-Wahab

    2012-12-01

    Full Text Available Citrobacter freundii A1 isolated from a sewage treatment facility was demonstrated to be able to effectively decolorize azo dyes as pure and mixed culture. This study reports on the investigation on the enzymatic systems involved. An assay performed suggested the possible involvement of flavin reductase (Fre as an azo reductase. A heterologouslyexpressed recombinant Fre from C. freundii A1 was used to investigate its involvement in the azo reduction process. Three model dyes were used, namely Acid Red 27 (AR27, Direct Blue 15 (DB15 and Reactive Black 5 (RB5. AR27 was found to be reduced the fastest by Fre, followed by RB5, and lastly DB15. Redox mediators nicotinamide adenine dinucleotide (NADH and riboflavin enhance the reduction, suggesting the redox activity of the enzyme. The rate and extent of reduction of the model dyes correlate well with the reduction potentials (Ep. The data presented here strongly suggest that Fre is one of the enzymes responsible for azo reduction in C. freundii A1, acting via an oxidation-reduction reaction.

  15. Synthesis and anion recognition studies of novel bis (4-hydroxycoumarin) methane azo dyes

    Science.gov (United States)

    Panitsiri, Amorn; Tongkhan, Sukanya; Radchatawedchakoon, Widchaya; Sakee, Uthai

    2016-03-01

    Four new bis (4-hydroxycoumarin) methane azo dyes were synthesized by the condensation of 4-hydroxycoumarin with four different azo salicylaldehydes and their structures were characterized by FT-IR, 1H NMR, 13C NMR, HRMS. Anion binding ability in dimethyl sulfoxide (DMSO) solutions with tetrabutylammonium (TBA) salts (F-, Cl-, Br-, I-, AcO- and H2PO4-) was investigated by the naked eye, as well as UV-visible spectroscopy. The sensor shows selective recognition towards fluoride and acetate. The binding affinity of the sensors with fluoride and acetate was calculated using UV-visible spectroscopic technique.

  16. Effect of Azo Dyes on the Thermal Degradation of Post-consumer Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Qin Dan

    2016-01-01

    Full Text Available Thermogravimetric analysis(TGA and pyrolysis gas chromatography mass spectrometry (Py-GC-MS investigations were carried out on the thermal degradation of white and red post-consumer polyester fabrics. The results show that red PET fabrics which was dyed with C.I. Disperse red 167 for its typical azo structure exhibits larger activation energy compared with white PET. The addition of azo dyes displays an inhibiting effect on the deep pyrolysis and the formation of biphenyl and bis(2-hydroxybutyl terephthalate produced by the free radical mechanism.

  17. Synthesis and application of new mordent and disperse azo dyes based on 2,4-dihydroxybenzophenone

    Directory of Open Access Journals (Sweden)

    BHARAT C. DIXIT

    2007-02-01

    Full Text Available Novel mordent and disperse azo dyes were prepared by the coupling of various diazo solutions of aromatic amines with 2,4-ihydroxybenzophenone. The resultant dyes were characterized by elemental analyses as well as IR and NMR spectral studies. The UV-visible spectral data have also been iscussed in terms of structural property relationship. The dyeing assessment of all the dyeswas evaluated on wool and polyester textile fibers. The dyeing of chrome treated (i.e., chrome mordented wool and polyesters was also monitored. The results show that a better hue was obtained on mordented fibers. The results of the anti-bacterial properties of the chrome dyes revealed that the toxicity of these dyes against bacteria is fairly good.

  18. Seasonal Energy Experimental Evaluation of a SBFBR for Treatment of the Azo Dye Direct Red 23

    OpenAIRE

    Morales-Guzmán F.; Romero R. J.; Domínguez-Patiño M. L.; Rodríguez-Martínez A.; Melgoza-Alemán Rosa María

    2012-01-01

    This paper shows the experimental energy evaluation for a Sequencing Batch Fluidized Bed Reactor (SBFBR) anaerobic/aerobic. The SBFBR was installed for the treatment of the Direct Red 23 azo dye (DR23 C. I. 29160). The evaluation of energy was made for summer and winter seasons. DR23 was selected for study because is not quickly biodegraded. DR23 is one of the most used dyes in the textile industry and it is used to dye cotton, linen and rayon fibers. DR23 is stable to light, easily absorbed ...

  19. Decolorization of Azo Dye (Orange MR) by an Autochthonous Bacterium, Micrococcus sp. DBS 2

    OpenAIRE

    Rajee, O.; PATTERSON, Jamila

    2011-01-01

    Soil and sediment samples obtained from Orange MR dye contaminated habitat were screened for heterotrophic bacterial population. The heterotrophic bacterial density of dye-contaminated soil was 2.14 × 106 CFU/g. The generic composition of heterotrophic bacterial population was primarily composed of 10% of Proteus sp., 15% Aeromonas sp., 20% Bacillus sp., 25% Pseudomonas sp. and 30% Micrococcus sp. The bacterial strain that decolorized the azo dye Orange MR up to 900 ppm was identified as Micr...

  20. Degradation of a mono sulfonated azo dye by an integrated bio sorption and anaerobic system

    International Nuclear Information System (INIS)

    A simulated textile effluent containing a mono sulphonated azo dye was fed to an anaerobic bioreactor in which a natural adsorbent, spent brewery grains (SBG), was incorporated. SABG is a by-product of the brewing industry and could act as adsorbent as well an electron shuttle (lignin fraction) in the dye degradation mechanism. Furthermore, it can also work as a conditioner for the anaerobic biomass. The influence of the dye (Acid Orange 7, AO7) concentration (60 and 150 mg/L) and the presence of SBG in the performance of upflow anaerobic sludge blanket reactor (UASB) was evaluated. (Author)

  1. The stability of textile azo dyes in soil and their impact on microbial phospholipid fatty acid profiles.

    Science.gov (United States)

    Imran, Muhammad; Shaharoona, Baby; Crowley, David E; Khalid, Azeem; Hussain, Sabir; Arshad, Muhammad

    2015-10-01

    The aim of this study was to examine the stability of structurally different azo dyes in soil and their impact on the microbial community composition by analyzing phospholipid fatty acid (PLFA) profiles. Sterile and non-sterile soils were amended with three azo dyes, including: Direct Red 81, Reactive Black 5 and Acid Yellow 19 at 160mgkg(-1) soil. The results showed that the azo dyes were quite stable and that large amounts of these dyes ranging from 17.3% to 87.5% were recoverable from the sterile and non-sterile soils after 14 days. The maximum amount of dye was recovered in the case of Direct Red 81. PLFA analysis showed that the azo dyes had a significant effect on microbial community structure. PLFA concentrations representing Gram-negative bacteria in dye-amended soil were substantially less as compared to the PLFA concentration of Gram-positive bacteria. Acid Yellow 19 dye had almost similar effects on the PLFA concentrations representing bacteria and fungi. In contrast, Reactive Black 5 had a greater negative effect on fungal PLFA than that on bacterial PLFA, while the opposite was observed in the case of Direct Red 81. To our knowledge, this is the first study reporting the stability of textile azo dyes in soil and their effects on soil microbial community composition. PMID:26074308

  2. Synthesis and investigation of antimicrobial activity and spectrophotometric and dyeing properties of some novel azo disperse dyes based on naphthalimides.

    Science.gov (United States)

    Shaki, Hanieh; Gharanjig, Kamaladin; Khosravi, Alireza

    2015-01-01

    A series of novel disperse dyes containing azo group were synthesized through a diazotization and coupling process. The 4-amino-N-2-aminomethylpyridine-1,8-naphthalimide was diazotized by nitrosylsulphuric acid and coupled with various aromatic amines such as N,N-diethylaniline, N,N-dihydroxyethylaniline, 8-hydroxyquinoline, and 2-methylindole. Chemical structures of the synthesized dyes were characterized by Fourier transform infrared (FTIR), differential scanning calorimetry (DSC), proton nuclear magnetic resonance ((1) H NMR), carbon nuclear magnetic resonance ((13) C NMR), elemental analysis, and ultraviolet-visible (UV-visible) spectroscopy. The spectrophotometric data of all dyes were evaluated in various solvents with different polarity. Eventually, the dyes were applied on polyamide fabrics in order to investigate their dyeing properties. The fastness properties of the dyed fabrics such as wash, light, and rubbing fastness degrees were measured by standard methods. Moreover, the color gamut of the synthesized dyes was measured on polyamide fabrics. Results indicated that some of the synthesized dyes were able to dye polyamide fabrics with deep shades. They had very good wash and rubbing fastness degrees and moderate-to-good light fastness on polyamide fabrics. The antibacterial and antifungal activities of the synthesized dyes were evaluated in soluble state and on the dyed fabrics. The results indicated that dye 2 containing N,N-dihydroxyethylaniline as coupler had the highest activity against all the bacteria and fungi used. PMID:25967675

  3. Impact of Photo-Induced Surface Adsorption of Azo-Dyes on the Liquid Crystal Anchoring Conditions

    Science.gov (United States)

    Statman, David

    2013-03-01

    Using optical techniques, we measured the anchoring conditions of azo-dye doped nematic liquid crystals on rubbed polyimide surfaces. Linearly polarized light induces the formation of a second easy axis on the polymer surface oriented toward the polarization direction of the pump laser beam. This additional easy axis is the result of photo-induced adsorption of the cis isomer of the azo dye. An effective easy axis is the weighted average of the original easy axis and this new easy axis.

  4. Bithiophene azo dyes bearing thiazole, benzothiazole and thiadiazole heterocycles : synthesis and comparative study of their photochromic properties

    OpenAIRE

    Castro, M. Cidália R.; Paulo J. Coelho; Fernandes, Sara S. M.; Fonseca, A. Maurício C.; Raposo, M. Manuela M.

    2012-01-01

    Although a large variety of diarylazo compounds are used in the design of optical materials, only a few reports concerning the photoisomerization of heterocyclic azo dyes can be found in the literature. In the last years our group reported for the first time the synthesis and characterization of heterocyclic azo dyes bearing thiophene and pyrrole moieties as thermally stable conducting materials, solvatochromic probes and nonlinear optical systems. The E/Z isomerizable N=N double bond within ...

  5. Electrochemical element on the base of carbon nano tubes, n-In P and on orange azo dye

    International Nuclear Information System (INIS)

    Properties of electrochemical element on the base of carbon nano tubes, n-In P and on orange azo dye are considered in this article. Investigation results of electrochemical elements on the base of carbon nano tubes, n-In P, water solution of orange azo dye and conductive glass are presented. It is shown that at increasing of electrolyte concentration the value of short circuit current and open circuit voltage of elements are increased.

  6. Biodegradation and detoxification of textile azo dyes by bacterial consortium under sequential microaerophilic/aerobic processes

    Science.gov (United States)

    Lade, Harshad; Kadam, Avinash; Paul, Diby; Govindwar, Sanjay

    2015-01-01

    Release of textile azo dyes to the environment is an issue of health concern while the use of microorganisms has proved to be the best option for remediation. Thus, in the present study, a bacterial consortium consisting of Providencia rettgeri strain HSL1 and Pseudomonas sp. SUK1 has been investigated for degradation and detoxification of structurally different azo dyes. The consortium showed 98-99 % decolorization of all the selected azo dyes viz. Reactive Black 5 (RB 5), Reactive Orange 16 (RO 16), Disperse Red 78 (DR 78) and Direct Red 81 (DR 81) within 12 to 30 h at 100 mg L-1 concentration at 30 ± 0.2 °C under microaerophilic, sequential aerobic/microaerophilic and microaerophilic/aerobic processes. However, decolorization under microaerophilic conditions viz. RB 5 (0.26 mM), RO 16 (0.18 mM), DR 78 (0.20 mM) and DR 81 (0.23 mM) and sequential aerobic/microaerophilic processes viz. RB 5 (0.08 mM), RO 16 (0.06 mM), DR 78 (0.07 mM) and DR 81 (0.09 mM) resulted into the formation of aromatic amines. In distinction, sequential microaerophilic/ aerobic process doesn’t show the formation of amines. Additionally, 62-72 % reduction in total organic carbon content was observed in all the dyes decolorized broths under sequential microaerophilic/aerobic processes suggesting the efficacy of method in mineralization of dyes. Notable induction within the levels of azoreductase and NADH-DCIP reductase (97 and 229 % for RB 5, 55 and 160 % for RO 16, 63 and 196 % for DR 78, 108 and 258 % for DR 81) observed under sequential microaerophilic/aerobic processes suggested their critical involvements in the initial breakdown of azo bonds, whereas, a slight increase in the levels of laccase and veratryl alcohol oxidase confirmed subsequent oxidation of formed amines. Also, the acute toxicity assay with Daphnia magna revealed the nontoxic nature of the dye-degraded metabolites under sequential microaerophilic/aerobic processes. As biodegradation under sequential microaerophilic

  7. Synthesis and antitumor evaluation of thiophene based azo dyes incorporating pyrazolone moiety

    Directory of Open Access Journals (Sweden)

    Moustafa A. Gouda

    2016-03-01

    Full Text Available A series of thiophene incorporating pyrazolone moieties 5a–f and 6a–c were synthesized via diazo coupling of diazonium salt of 3-substituted-2-amino-4,5,6,7-tetrahydrobenzo[b]thiophenes 1a–c with 3-methyl-1H-pyrazol-5(4H-one, 3-methyl-1-phenyl-1H-pyrazol-5(4H-one or 3-amino-1H-pyrazol-5(4H-one, respectively. Newly synthesized dyes were applied to polyester fabric as disperse dyes in which their color measurements and fastness properties were evaluated. These dyes showed generally red to blue shifted color with high extinction coefficient in comparison with aniline-based azo dyes. The antitumor activity of the synthesized dyes was evaluated. The results showed clearly that most of them exhibited good activity and compounds 5c and 5d exhibited moderate activity.

  8. Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Alya M. Al-Etaibi

    2016-06-01

    Full Text Available The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated.

  9. Dyeing of Polyester with Disperse Dyes: Part 2. Synthesis and Dyeing Characteristics of Some Azo Disperse Dyes for Polyester Fabrics.

    Science.gov (United States)

    Al-Etaibi, Alya M; Alnassar, Huda S; El-Apasery, Morsy Ahmed

    2016-01-01

    The goal of this study was to utilize carrier for accelerating the rate of dyeing not only to enhance dyeing of polyester fabrics dyed with disperse dyes 3a,b, but also to save energy. Both the color strength expressed as dye uptake and the fastness properties of the dyed fabrics were evaluated. PMID:27367659

  10. Sonolytic and sonocatalytic degradation of azo dyes by low and high frequency ultrasound

    International Nuclear Information System (INIS)

    The study describes degradation of two azo dyes at low and high frequency ultrasound (US) to compare their reactivity and to assess the impacts of frequency, OH·, chemical structure and soluble/nonsoluble additives. Low frequency US alone was found totally ineffective for bleaching the dyes even after 2-h irradiation, while high frequency provided significant color decay in 30-min contact. The result was attributed to larger number of oscillations at high frequency that allowed a larger fraction of OH· ejection to the bulk liquid. The difference in the rates of dye degradation was due to different substituents around the azo bonds that dictated the reactivities of the dyes with OH· and other species. The performance of low frequency US was remarkably improved and exceeded that of high frequency in the presence of CCl4, nano-sized TiO2 and zero-valent copper. The effect was attributed to the advantage of low frequency for long bubble-life time, high collapse temperatures, turbulent flow conditions and high sonoluminescence intensity. The efficacies of the additives in terms of the reduction in dye concentration per unit mass of additive were: TiO2 > CCl4 > Cu, regardless of the dye structure and the operation frequency. Much better performance of TiO2 than Cu was attributed to its larger surface area with a slight positive charge on it and to the effect of stable sonoluminescence that may have induced photocatalytic properties on semiconductor surface.

  11. Fluorescent Sensing of Chlorophenols in Water Using an Azo Dye Modified β-Cyclodextrin Polymer

    Directory of Open Access Journals (Sweden)

    Bhekie B. Mamba

    2011-04-01

    Full Text Available A water soluble azo dye modified β-cyclodextrin polymer 4 was synthesized and used as a chemosensor for the detection of chlorinated phenols, model chlorinated by-products (CBPs of water treatment for drinking purposes. The characterization of the intermediates and the azo dye modified β-CD polymer was done by UV/Vis Spectrophotometry, FT-IR and 1H-NMR spectroscopies. The chlorophenols were capable of quenching the fluorescence of the polymer. The polymer showed greater sensitivity towards 2,4-dichlorophenol, with a sensitivity factor of 0.35 compared to 0.05 and 0.12 for phenol and 4-chlorophenol, respectively. The stability constants (Ks of the pollutants were also determined by the Benesi-Hildebrand method to be 2.104 × 103 M−1 for 2,4-dichlorophenol and 1.120 × 102 M−1 for 4-chlorophenol.

  12. Synthesis and Application of Some Azo and Azomethine Dyes Containing Pyrazolone Moiety

    Institute of Scientific and Technical Information of China (English)

    RIZK, Hala, F; El-BORAl, Mohamed, A; El-HEFNAWY, Gad, B; El-SAYED, Hatem, F

    2009-01-01

    3-Amino-1-phenyl-4,5-dihydro-1H-pyrazol-5-one (1) was used as starting material for the synthesis of a num- ber of azo compounds 3a-3c and azomethine derivative 4. The deblocking of 3a-3c and 4 gave rise to 5a-5c and 6 in which a free amino was revealed. The diazonium salts of 5a-5c and 6 were coupled with several phenols to produce a number of bis azo compounds 7a-7c and 8a-8c with azomethine in position 4 and azoic group in position 3. The prepared dyes were structurally confirmed by elemental analysis, spectral methods and applied to different fibers (wool, polyester and blend of wool/polyester) as disperse dyes and their fastness properties were measured.

  13. Ultrafast degradation of azo dyes catalyzed by cobalt-based metallic glass

    Science.gov (United States)

    Qin, X. D.; Zhu, Z. W.; Liu, G.; Fu, H. M.; Zhang, H. W.; Wang, A. M.; Li, H.; Zhang, H. F.

    2015-12-01

    Reactivity and mass loss are considered mutually exclusive in conventional zero-valent metal (ZVM) technology to treat environmental contaminants. Here, we report the outstanding performance of Co-based metallic glass (MG) in degrading an aqueous solution of azo dye, thus eliminating this trade-off. Ball-milled Co-based MG powders completely degrade Acid Orange II at an ultrafast rate. The surface-area-normalized rate constant of Co-based MG powders was one order of magnitude higher than that of Co-based crystalline counterparts and three orders of magnitude higher than that of the widely studied Fe0 powders. The coordinatively unsaturated local structure in Co-based MG responds to the catalysis for degradation, resulting in very low mass loss. Wide applicability and good reusability were also present. Co-based MG is the most efficient material for azo dye degradation reported thus far, and will promote the practical application of MGs as functional materials.

  14. Performance of microbial fuel cell coupled constructed wetland system for decolorization of azo dye and bioelectricity generation.

    Science.gov (United States)

    Fang, Zhou; Song, Hai-Liang; Cang, Ning; Li, Xian-Ning

    2013-09-01

    A microbial fuel cell coupled constructed wetland (planted with Ipomoea aquatica) system (planted CW-MFC) was used for azo dye decolorization. Electricity was simultaneously produced during the co-metabolism process of glucose and azo dye. A non-planted and an open-circuit system were established as reference to study the roles of plants and electrodes in azo dye decolorization and electricity production processes, respectively. The results indicated that plants grown in cathode enhanced the cathode potential and slightly promoted dye decolorization efficiency. The electrodes promoted the dye decolorization efficiency in the anode. The planted CW-MFC system achieved the highest decolorization rate of about 91.24% and a voltage output of about 610 mV. The connection of external circuit promoted the growth of electrogenic bacteria Geobacter sulfurreducens and Beta Proteobacteria, and inhibited the growth of Archaea in anode. PMID:23867535

  15. Phytoremediation of industrial effluent containing azo dye by model up-flow constructed wetland

    Institute of Scientific and Technical Information of China (English)

    S.A.Ong; K.Uchiyama; D.Inadama; Y.Ishida; K.Yamagiwa

    2009-01-01

    This study assessed the treatment of azo dye Acid Orange 7(AO7)containing wastewater by laboratory-scale up-flow constructed wetland(UFCW)with and without supplementary aeration.The supplementary aeration could effectively control the ratio of anaerobic and aerobic zones in the UFCW reactor.The results dearly show the supplementary aeration boosted the biodegradation of organic pollutants and mineralization of intermediate aromatic amines formed by AO7 degradation.

  16. FACTORS AFFECTING THE REMOVAL OF A BASIC AND AN AZO DYE FROM ARTIFICIAL SOLUTIONS BY ADSORPTION USING ACTIVATED CARBON

    OpenAIRE

    Albroomi, H I; ElSayed, Mohamed; Baraka, A.; Abdelmaged, M A

    2014-01-01

    Decolourisation of wastewater, particularly from textile industries, is one of the major environmental concerns these days. Current methods for removing dyes from wastewater are costly and cannot effectively be used to treat wide range of such wastewater. This work describes the use of commercial available granular activated carbon (GAC) as an efficient adsorbent material for dyes removal. Aqueous solutions of various basic dye Methylene Blue (MB) and azo-dye Tartrazine with concentrations 5-...

  17. Process and kinetics of azo dye decolourization in bioelectrochemical systems: effect of several key factors.

    Science.gov (United States)

    Yang, Hou-Yun; He, Chuan-Shu; Li, Lei; Zhang, Jie; Shen, Jin-You; Mu, Yang; Yu, Han-Qing

    2016-01-01

    This study explored the influence of several key factors on the process and kinetics of azo dye decolourization in bioelectrochemical systems (BESs), including cathode potential, dissolved oxygen (DO) concentration of catholyte and biofilm formed on the cathode. The results show that azo dye methyl orange (MO) decolourization in the BES could be well described with the pseudo first-order kinetics. The MO decolourization efficiency increased from 0 to 94.90 ± 0.01% and correspondingly the reaction rate constant increased from 0 to 0.503 ± 0.001 h(-1) with the decrease in cathodic electrode potential from -0.2 to -0.8 V vs Ag/AgCl. On the contrary, DO concentration of the catholyte had a negative impact on MO decolourization in the BES. When DO concentration increased from zero to 5.80 mg L(-1), the MO decolourization efficiency decreased from 87.19 ± 4.73% to 27.77 ± 0.06% and correspondingly the reaction rate constant reduced from 0.207 ± 0.042 to 0.033 ± 0.007 h(-1). Additionally, the results suggest that the biofilm formed on the cathode could led to an adverse rather than a positive effect on azo dye decolourization in the BES in terms of efficiency and kinetics. PMID:27270398

  18. Density functional theory study of new azo dyes with different π-spacers for dye-sensitized solar cells

    Science.gov (United States)

    Bagheri Novir, Samaneh; Hashemianzadeh, Seyed Majid

    2015-05-01

    Some of new azo-based metal-free dyes with different π-conjugation spacers, such as carbazole, fluorene, pyrrole, thiophene, furan and thiazole, have been investigated with density functional theory (DFT) and time-dependent DFT (TDDFT) calculations. Theoretical calculations allow us to quantify factors such as light harvesting efficiency (LHE), electron injection driving force (ΔGinject) and the weight of the LUMO orbital on the carboxylic group (QLUMO) related to the short-circuit photocurrent density (Jsc), and to evaluate both charge recombination between the semiconductor conduction band electrons and the oxidized dyes and/or electrolyte, and also the shift of the conduction band of the semiconductor as a result of the adsorption of the dyes onto the semiconductor surface, associated with the open-circuit photovoltage (Voc). According to the results, we could predict that how the π-conjugation spacers influence the Jsc as well as the Voc of DSSCs. Among these dyes, the carbazole and fluorene-based dyes (dyes 1 and 2) show the highest LHE, ΔGinject, QLUMO, and the slowest recombination rate. Consequently, the obtained results show that the carbazole and fluorene-based dyes could have the better Jsc and Voc compared to the other dyes.

  19. Kinetics and Equilibrium Studies on Adsorption of Acid Red 18 (Azo-Dye) Using Multiwall Carbon Nanotubes (MWCNTs) from Aqueous Solution

    OpenAIRE

    Shirmardi, Mohammad; Mesdaghinia, Alireza; MAHVI, Amir Hossein; Nasseri, Simin; Nabizadeh, Ramin

    2012-01-01

    Azo dyes are one of the synthetic dyes that are used in many textile industries. Adsorption is one of the most effective techniques for removal of dye-contaminated wastewater. In this work, efficiency of multiwalled carbon nanotubes (MWCNTs) as an adsorbent for removal of Acid Red 18 (azo-dye) from aqueous solution was determined. The parameters affecting the adsorption process such as contact time, pH, adsorbent dosage, and initial dye concentration were studied. Experimental results have sh...

  20. Functional behavior of bio-electrochemical treatment system with increasing azo dye concentrations: Synergistic interactions of biocatalyst and electrode assembly.

    Science.gov (United States)

    Sreelatha, S; Velvizhi, G; Naresh Kumar, A; Venkata Mohan, S

    2016-08-01

    Treatment of dye bearing wastewater through biological machinery is particularly challenging due to its recalcitrant and inhibitory nature. In this study, functional behavior and treatment efficiency of bio-electrochemical treatment (BET) system was evaluated with increasing azo dye concentrations (100, 200, 300 and 500mg dye/l). Maximum dye removal was observed at 300mg dye/l (75%) followed by 200mg dye/l (65%), 100mg dye/l (62%) and 500mg dye/l (58%). Concurrent increment in dye load resulted in enhanced azo reductase and dehydrogenase activities respectively (300mg dye/l: 39.6U; 4.96μg/ml). Derivatives of cyclic voltammograms also supported the involvement of various membrane bound redox shuttlers, viz., cytochrome-c, cytochrome-bc1 and flavoproteins during the electron transfer. Bacterial respiration during BET operation utilized various electron acceptors such as electrodes and dye intermediates with simultaneous bioelectricity generation. This study illustrates the synergistic interaction of biocatalyst with electrode assembly for efficient treatment of azo dye wastewater. PMID:27067459

  1. Biodegradation of azo and heterocyclic dyes by Phanerochaete chrysosporium.

    OpenAIRE

    Cripps, C.; Bumpus, J A; Aust, S D

    1990-01-01

    Biodegradation of Orange II, Tropaeolin O, Congo Red, and Azure B in cultures of the white rot fungus, Phanerochaete chrysosporium, was demonstrated by decolarization of the culture medium, the extent of which was determined by monitoring the decrease in absorbance at or near the wavelength maximum for each dye. Metabolite formation was also monitored. Decolorization of these dyes was most extensive in ligninolytic cultures, but substantial decolorization also occurred in nonligninolytic cult...

  2. Decolorization of Remazol Black-B azo dye in soil by fungi

    Directory of Open Access Journals (Sweden)

    Azeem Khalid*, Sadia Batool, Muhammad Tariq Siddique, Zilli Huma Nazli, Riffat Bibi, Shahid Mahmood and Muhammad Arshad

    2011-04-01

    Full Text Available Textile industry is known to release huge amount of dyes in the water and soil environments during the dyeingprocess. The present study was planned with the aim to remove azo dye toxicants from the soil using fungal strains.The fungi were isolated by using Remazol Black-B azo dye as the sole source of C and N. Ten isolates were initiallyselected for testing their decolorization potential in the liquid medium. Three most effective strains were used tostudy the decolorization of Remazol Black-B in soil. The strain S4 was found to be very effective in removing thedye Remazol Black-B from liquid medium as well as in soil suspension. More than 95% decolorization by the strainS4 was observed in soil under optimal incubation conditions. Overall, the dye decolorization was maximum at 100mg dye kg-1 soil at pH 7-8 under static conditions. Glucose, moisture and aeration also affected the decolorizationefficacy of the fungal strain in soil. This study implies that fungi could be used for bioremediation of dyecontaminatedsites.

  3. Simultaneous determination of three azo dyes in food product by ion mobility spectrometry.

    Science.gov (United States)

    Jiao, Jiandong; Wang, Jinfeng; Li, Mingfeng; Li, Junqing; Li, Qihong; Quan, Qinbo; Chen, Jinquan

    2016-07-01

    Color is an important property for food evaluation. Synthetic azo dyes are usually used in food product to obtain better appearance because of their stability and low cost. However, such dyes should be strictly controlled because of their potential threat to human health. A simple, rapid and sensitive method has been developed to determine orange II, allura red, and para red simultaneously by ion mobility spectrometry. The three dyes could be separated at the same time and the migration time of orange II, allura red, and para red are 12.070±0.010, 8.180±0.015, and 11.037±0.016ms, respectively. The effects of different parameters, such as pH, solvent, percentage of water, were investigated to establish the optimal condition. The detection limits were 0.1, 0.05, and 0.2μg/mL for orange II, allura red, and para red, respectively. The recoveries of the three azo dyes from jellies were all higher than 81%. The developed method is fast and accurate for the detection of the three synthetic dyes. PMID:27235999

  4. Removal of anionic azo dyes from aqueous solution by functional ionic liquid cross-linked polymer

    International Nuclear Information System (INIS)

    Highlights: • Equilibrium, kinetic and thermodynamic of adsorption of dyes onto PDVB-IL was investigated. • PDVB-IL has a high adsorption capacity to treat dyes solution. • Higher adsorption capacity is due to the functional groups of PDVB-IL. • Molecular structure of dyes influences the adsorption capacity. -- Abstract: A novel functional ionic liquid based cross-linked polymer (PDVB-IL) was synthesized from 1-aminoethyl-3-vinylimidazolium chloride and divinylbenzene for use as an adsorbent. The physicochemical properties of PDVB-IL were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis. The adsorptive capacity was investigated using anionic azo dyes of orange II, sunset yellow FCF, and amaranth as adsorbates. The maximum adsorption capacity could reach 925.09, 734.62, and 547.17 mg/g for orange II, sunset yellow FCF and amaranth at 25 °C, respectively, which are much better than most of the other adsorbents reported earlier. The effect of pH value was investigated in the range of 1–8. The result shows that a low pH value is found to favor the adsorption of those anionic azo dyes. The adsorption kinetics and isotherms are well fitted by a pseudo second-order model and Langmuir model, respectively. The adsorption process is found to be dominated by physisorption. The introduction of functional ionic liquid moieties into cross-linked poly(divinylbenzene) polymer constitutes a new and efficient kind of adsorbent

  5. Tratamiento del Colorante Azo Rojo Directo 23 mediante Reactores Discontinuos Secuenciados Anaerobios/Aerobios Treatment of Direct Red 23 Azo Dye by Anaerobic/Aerobic Sequencing Batch Reactors

    Directory of Open Access Journals (Sweden)

    Fernanda Morales-Guzmán

    2009-01-01

    Full Text Available Se evaluó el tratamiento del colorante azo Rojo Directo 23 mediante un proceso anaerobio/aerobio integrado en un sólo reactor. Se utilizaron dos reactores: uno de lecho expandido con carbón activado granular como mediador redox y otro conteniendo la biomasa suspendida, ambos operados en discontinuo. Se evaluó la eficiencia del proceso mediante la reducción y transformación del colorante a aminas aromáticas totales en la fase anaerobia y la degradación de éstas en la fase aerobia. La eliminación del colorante fue por microorganismos y no por adsorción en el carbón activado granular. Las concentraciones de colorante utilizadas fueron de 25 a 100 mg L-1. En el reactor de lecho expandido la eficiencia de degradación global del colorante fue del 90 % y la eliminación de las aminas formadas fue del 100 %.The treatment of the azo dye Direct Red 23 was evaluated by an anaerobic/aerobic process done in a single reactor. Two reactors were used: one was an expanded-bed with granular activated carbon as redox mediator and the other containing the suspended biomass, both operated in batch mode. The efficiency of the process was evaluated by the reduction and transformation of the azo dye to total aromatic amines in the anaerobic phase and the degradation of these in the aerobic phase. The elimination of azo dye direct red was by microorganisms and not by adsorption in the granular activated carbon. The concentration of azo dye used was of 25 to 100 mg L-¹. In the expanded-bed reactor the removal efficiency of the dye was 90 % and the elimination of the amines formed was of 100 %.

  6. Synthesis, spectroscopic, thermal and electrochemical studies on thiazolyl azo based disperse dyes bearing coumarin

    Science.gov (United States)

    Özkütük, Müjgan; İpek, Ezgi; Aydıner, Burcu; Mamaş, Serhat; Seferoğlu, Zeynel

    2016-03-01

    In this study, seven novel thiazolyl azo disperse dyes (6a-g) were synthesized and fully characterized by FT-IR, 1H NMR, 13C NMR, and mass spectral techniques. The electronic absorption spectra of the dyes in solvents of different polarities cover a λmax range of 404-512 nm. The absorption properties of the dyes changed drastically upon acidification. This was due to the protonation of the nitrogen in the thiazole ring, which in turn increased the donor-acceptor interplay of the π system in the dyes, and therefore increased the absorption properties of the prepared dyes. Thermal analysis showed that these dyes are thermal stable up to 269 °C. Additionally, the electrochemical behavior of the dyes (6a-g) were investigated using cyclic voltammetric and chronoamperometric techniques, in the presence of 0.10 M tetrabutylammonium tetrafluoroborate, in dimethylsulfoxide, at a glassy carbon electrode. The number of transferred electrons, and the diffusion coefficient were determined by electrochemical methods. The results showed that, for all the dyes, one oxidation peak and two reduction peaks were observed.

  7. Experimental data for synthesis of bi-metalized chitosan particle for attenuating of an azo dye from wastewater.

    Science.gov (United States)

    Hajivandi, Abdollah; Farjadfard, Sima; Ramavandi, Bahman; Akbarzadeh, Samad

    2016-06-01

    In this data article, we introduce data acquired from new adsorbent, bi-metalized chitosan particle that is successfully synthesized and applied to remove the orange II dye, an azo dye, from textile wastewater. The adsorbent was meso- and macro-porous material with BET surface area of 12.69 m(2)/g and pHzpc 6.6. The simulated textile-wastewater can be significantly treated using a relatively low quantity of the adsorbent. Overall, the use of bi-metalized chitosan particle can be considered a promising method for eliminating the azo dye from wastewater effectively. Accordingly, these data will be useful for decolorizing of azo dyes from textile wastewater. PMID:26955651

  8. The cobalt(II salt of the azo dye Orange G

    Directory of Open Access Journals (Sweden)

    Maurice O. Okoth

    2010-10-01

    Full Text Available Crystallizing the cobalt(II salt of the azo dye Orange G from water was found to give the solvent-separated ion-pair species hexaaquacobalt(II 7-oxo-8-(2-phenylhydrazin-1-ylidene-7,8-dihydronaphthalene-1,3-disulfonate tetrahydrate, [Co(H2O6](C16H10N2O7S2·4H2O. The asymmetric unit of the cobalt(II salt contains three independent octahedral [Co(OH26]2+ cations, three azo anions, all with similar configurations, and 12 uncoordinated water molecules. The structure is closely related to that of one of the known magnesium analogues. Both structures have Z′ = 3, feature nearly planar azo anions [maximum displacement of azo-N atoms from the plane of the phenyl ring = 0.058 (7 Å] in their hydrazone tautomeric form, form layer structures with hydrophilic and hydrophobic layers alternating along the b-axis direction, and are stabilized by an extensive network of hydrogen bonds..

  9. Properties of purified Orange II azoreductase, the enzyme initiating azo dye degradation by Pseudomonas KF46.

    Science.gov (United States)

    Zimmermann, T; Kulla, H G; Leisinger, T

    1982-12-01

    Orange II azoreductase [NAD(P)H: 1-(4'-sulfophenylazo)-2-naphthol oxidoreductase], an enzyme catalyzing the reductive cleavage of the azo bridge of Orange II and related dyes, was purified to electrophoretic homogeneity from Pseudomonas species, strain KF46. This organism utilized carboxy-Orange II [1-(4'-carboxyphenylazo)-2-naphthol] but not Orange II as the sole source of carbon, energy, and nitrogen. Orange II azoreductase was induced 80-fold by both Orange II and carboxy-Orange II. With two successive runs of affinity chromatography using two chromatographic media with different triazinyl dyes as ligands, the enzyme was purified 120-fold with 43% yield. The purified enzyme is a monomer with a molecular weight of 30,000. Its Km values were 1.5 microM for both Orange II and carboxy-Orange II, 5 microM for NADPH, and 180 microM for NADH. A survey of the efficiency of various Orange dyes as substrates for Orange II azoreductase showed that: (a) a hydroxy group in the 2-position of the naphthol ring is required; (b) charged groups in proximity to the azo group hinder the reaction; (c) a second polar substituent on the dye molecule impedes the reaction; (d) electron-withdrawing groups on the phenyl ring accelerate the reaction. PMID:7160382

  10. Revealing characteristics of mixed consortia for azo dye decolorization: Lotka-Volterra model and game theory.

    Science.gov (United States)

    Chen, Bor-Yann

    2007-10-22

    This study provides a novel explanation to put forward, in Lotka-Volterra competition model and game theory, interspecific competition in bioaugmentation using constructed mixed consortia for azo dye decolorization. As mixed cultures are regularly used in industrial dye-laden wastewater treatment, understanding species competition of mixed consortia is apparently of great importance to azo dye decolorization. In aerobic growth conditions, Escherichia coli DH5alpha owned a growth advantage to out-compete Pseudomonas luteola due to preferential growth rate of DH5alpha. However, in static decolorization conditions DH5alpha surrendered some proportion of its advantage (i.e., a decrease in its competitive power for metabolite stimulation) to enhance color removal of P. luteola for total coexistence. In aerobic growth, DH5alpha had its growth advantage to exclude P. luteola for dominance (i.e, conflict strategy) according to competitive exclusion principle. In static decolorization conditions, as the removal of a common dye threat was crucial to both species for survival, both species selected cooperation strategy through metabolite stimulation of DH5alpha to enhance effective decolorization of P. luteola for long-term sustainable management. This analysis of game theory clearly unlocked unsolved mysteries in previous studies. PMID:17499918

  11. Adsorption of the reactive azo dyes onto NH4Cl-induced activated carbon

    Directory of Open Access Journals (Sweden)

    Sakine Shekoohiyan

    2016-03-01

    Full Text Available Background: The efficacy of NH4Cl-induced activated carbon (NAC was examined in order to adsorb RR198, an azo reactive model dye, from an aqueous solution. Methods: The effects of pH (3 to 10, adsorbent dose (0.1 to 1.2 g/L, dye concentration and contact time on the adsorption efficiency were investigated. Results: The results showed that the removal of dye was highest at a solution pH of 7 and a powder dose of 1.1 g/L. The 85.9%, 72.6% and 65.4% removal of RR198 was obtained for a concentration of 25, 50 and 100 mg/L, respectively, at a relatively short contact time of 30 minutes, and at optimum pH and NAC concentrations of 1 g/L. The experimental data for kinetic analysis illustrated a best fit to the pseudo-second-order model. The study data on equilibrium were modeled using Langmuir, Freundlich and Dubinin–Radushkevich models; the Langmuir equation provided the best fit for the data. Conclusion: Therefore, the NAC appears to be an efficient and appropriate adsorbent for the removal of reactive azo dyes from waste streams.

  12. An improved method for removal of azo dye orange II from textile effluent using albumin as sorbent.

    Science.gov (United States)

    Ohashi, Tadashi; Jara, Alícia M T; Batista, Anabelle C L; Franco, Luciana O; Barbosa Lima, Marcos A; Benachour, Mohand; Alves da Silva, Carlos A; Campos-Takaki, Galba M

    2012-01-01

    Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA) in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v), respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL₅₀ equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes. PMID:23201641

  13. An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent

    Directory of Open Access Journals (Sweden)

    Tadashi Ohashi

    2012-11-01

    Full Text Available Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a proportion of 1:3 (v/v, respectively. The synthetic effluent did not show toxicity to the microcrustacean Artemia salina, and showed a CL50 equal to 97 µg/mL to azo dye orange II. Additionally, the methodology was effective in removing the maximum of orange II using BSA by adsorption at pH 3.5 which mainly attracted ions to the azo dye during the adsorption process. This suggests that this form of treatment is economical and easy to use which potentially could lead to bovine serum albumin being used as a sorbent for azo dyes.

  14. Removal of azo and anthraquinone reactive dyes from industrial wastewaters using MgO nanoparticles

    International Nuclear Information System (INIS)

    In the present investigation, a porous MgO powder was synthesized and tested for the removal of dyes from aqueous solution. The size of the MgO particles was in the range of 38-44 nm, with an average specific surface area of 153.7 m2/g. Adsorption of reactive blue 19 and reactive red 198 was conducted to model azo and anthraquinone dyes at various MgO dosages, dye concentrations, solution pHs and contact times in a batch reactor. Experimental results indicate that the prepared MgO powder can remove more than 98% of both dyes under optimum operational conditions of a dosage of 0.2 g, pH 8 and a contact time of 5 min for initial dye concentrations of 50-300 mg/L. The isotherm evaluations revealed that the Langmuir model attained better fits to the experimental equilibrium data than the Freundlich model. The maximum predicted adsorption capacities were 166.7 and 123.5 mg of dye per gram of adsorbent for RB 19 and RR 198, respectively. In addition, adsorption kinetic data followed a pseudo-second-order rate for both tested dyes.

  15. Optical Parameters and Absorption of Azo Dye and Its Metal-Substituted Compound Thin Films

    Institute of Scientific and Technical Information of China (English)

    魏斌; 吴谊群; 顾冬红; 干福熹

    2003-01-01

    We determine the complex refractive indices N ( N = n - ik), dielectric constants ε(ε = ε1 - iε2), and absorption coefficients α of a new azo dye [2-(6-methyl-2-benzothiazolyazo)-5-diethylaminophenol(MBADP)]-doped polymer and its nickel- and zinc-substituted compounds(Ni-MBADP and Zn-MBADP) spin-coated thin films from a scanning ellipsometer in the wavelength 400-700 nm region. Metal chelation strongly (about one times) enhances the optical and dielectric parameters at the peaks and results in a large bathochromic shift (50-60nm) of absorption band. Bathochromic shift of Ni-MBADP is about 10nm larger than that of Zn-MBADP due to different spatial configurations formed in the metal-azo complexes.

  16. Optical characterization of azo dye-based electro-optic polymer films

    Science.gov (United States)

    Ferm, Paul M.; Horn, Keith A.; Beeson, Karl W.; McFarland, Michael J.; Schwind, David R.; Yardley, James T.

    1994-01-01

    We have investigated the photochemistry and optical properties of an azo dye-based electro- optic (EO) copolymer, methacrylate-bound Disperse Red 1/methylmethacrylate (MA1). We present a complete picture of the optical properties of the copolymer at wavelengths ranging from 200 nm to 1800 nm with detection sensitivity over 6 orders of magnitude. We describe intrinsic measurements of absorption loss and also describe how temperature and radiation affect absorption loss. Photochemical investigations reveal details concerning photodelineation of waveguides in MA1. Irreversible photodegradation of the azo chromophore proceeds with both visible and ultra-violet radiation and a quantum yield of 2 X 10-5 is found for 475 nm radiation in MA1.

  17. Metabolism of azo dyes by Lactobacillus casei TISTR 1500 and effects of various factors on decolorization.

    Science.gov (United States)

    Seesuriyachan, Phisit; Takenaka, Shinji; Kuntiya, Ampin; Klayraung, Srikarnjana; Murakami, Shuichiro; Aoki, Kenji

    2007-03-01

    Lactobacillus casei TISTR 1500 was isolated from soil of a dairy wastewater treatment plant and selected as the most active azo dye degrader of 19 isolates. Growing cells and freely suspended cells of this strain completely degraded methyl orange, thereby decolorizing the medium. The strain stoichiometrically converted methyl orange to N,N-dimethyl-p-phenylenediamine and 4-aminobenzenesulfonic acid, which were identified by HPLC, GC, and GC-MS analyses. The enzyme activity responsible for the cleavage of the azo bond of methyl orange was localized to the cytoplasm of cells grown on modified MRS medium containing methyl orange. The effect of sugars, oligosaccharides, organic acids, metal ions, pHs, oxygen and temperatures on methyl orange decolorization by freely suspended cells was investigated. The optimal conditions for the decolorization of methyl orange by the Lactobacillus casei TISTR 1500 are incubation at 35 degrees C and pH 6 with sucrose provided as the energy source. PMID:17254626

  18. Effect of temperature on the photoalignment of azo dyes in thin films

    Science.gov (United States)

    Mikulich, V. S.; Murauski, An. A.; Muravsky, Al. A.; Agabekov, V. E.

    2016-03-01

    The temperature dependences of the induced dichroic ratios (DRs) of azo dyes after their photoalignment in thin films 80 to 200 nm thick are studied. It is found that the DR values of layers containing dyes of the benzeneazodiphenyl series fall from 6.0 to 1.6 as the temperature rises from 60 to 130°C, respectively. A reduction in induced DR as the temperature rises (from 20 to 100°C) is also observed for the thin films of the dyes of benzeneazo-5,5'-dioxodibenzothiophene group. The absence of induced DR after irradiation with polarized light at 100°C indicates there is no alignment of molecules at this temperature.

  19. Azo dye degradation by Phanerochaete chrysosporium in the medium enriched with nitrogen in the presence of primary co-substrate

    OpenAIRE

    Marcus Vinicius Freire Andrade; Karla Mayara Lima da Silva; João Paulo da Silva Siqueira; Carlos Ronald Pessoa Wanderley; Rinaldo dos Santos Araújo; Gloria Marinho; Kelly Rodrigues

    2013-01-01

    This work sought to evaluate the ability of fungi Phanerochaete chryosporium to degrade congo red azo dye in batch reactor, evaluate the influence of glucose and wheat bran as co-substrates on the removal of the dye in the medium and investigate the influence of ammonium chloride, ammonium nitrate and ammonium sulfate as the inorganic nitrogen source for the process. Wheat bran was not effective satisfactorily for the removal of dye and organic matter had no desired effect for the removal of ...

  20. Integration of photocatalysis and biological treatment for azo dye removal--application to AR183.

    Science.gov (United States)

    Chebli, Derradji; Fourcade, Florence; Brosillon, Stephan; Nacef, Saci; Amrane, Abdeltif

    2011-04-01

    The feasibility of coupling photocatalysis with biological treatment to treat effluents containing azo dyes was examined in this work. With this aim, the degradation of Acid Red 183 was investigated. The very low biodegradability of AR183 was confirmed beforehand by measuring the biological oxygen demand (BOD5). Photocatalysis experiments were carried out in a closed-loop step photoreactor. The reactor walls were covered by TiO2 catalyst coated on non-woven paper, and the effluent flowed over the photocatalyst as a thin falling film. The removal of the dye was 82.7% after 4 h, and a quasi-complete decolorization (98.5%) was obtained for 10 h of irradiation (initial concentration 100 mg L(-1)). The decrease in concentration followed pseudo-first-order kinetics, with a constant k of 0.47 h(-1). Mineralization and oxidation yields were 80% and 75%, respectively, after 10 h of pretreatment. Therefore, even if target compound oxidation occurs (COD removal), indicating a modification to the chemical structure, the concomitant high mineralization was not in favour of subsequent microbial growth. The BOD5 measurement confirmed the non-biodegradability of the irradiated solution, which remained toxic since the EC50 decreased from 35 to 3 mg L(-1). The proposed integrated process appeared, therefore, to be not relevant for the treatment of AR183. However, this result should be confirmed for other azo dyes. PMID:21877531

  1. Chitosan beads as barriers to the transport of azo dye in soil column.

    Science.gov (United States)

    Lazaridis, Nikolaos K; Keenan, Helen

    2010-01-15

    The development of chitosan-based materials as useful adsorbent polymeric matrices is an expanding field in the area of adsorption science. Although chitosan has been successfully used for the removal of dyes from aqueous solutions, no consideration is given to the removal of dyes from contaminated soils. Therefore this study focuses on the potential use of chitosan as an in situ remediation technology. The chitosan beads were used as barriers to the transport of a reactive dye (Reactive Black 5, RB5) in soil column experiments. Batch sorption experiments, kinetic and equilibrium, were performed to estimate the sorption behavior of both chitosan and soil. The chitosan beads were prepared in accordance with published literature and a synthetic soil was prepared by mixing quantities of sand, silt and clay. The synthetic soil was classified according to British Standards. Calcium chloride was used as tracer to define transport rates and other physical experimental parameters. Dye transport reaction parameters were determined by fitting dye breakthrough curves (BTCs) to the HYDRUS-1D version 4.xx software. Fourier Transform-Infra Red (FT-IR) spectroscopy was used to reveal the sorption mechanism. The study showed that chitosan exhibited a high sorption capacity (S(max)=238 mg/g) and pseudo-first sorption rate (k(1)=1.02 h(-1)) coupled with low swelling and increased retardation for the azo dye tested. Thus it has potential as a Permeable Reactive Barrier (PRB) for containment and remediation of contaminated sites. PMID:19740603

  2. pI-Control in comparative fluorescence gel electrophoresis (CoFGE) using amphoteric azo dyes

    Czech Academy of Sciences Publication Activity Database

    Hanneken, M.; Šlais, Karel; König, S.

    2015-01-01

    Roč. 8, SEP (2015), s. 36-39. ISSN 2212-9685 Institutional support: RVO:68081715 Keywords : comparative fluorescence gel * electrophoresis * protein grid * azo dyes Subject RIV: CB - Analytical Chemistry, Separation http://ac.els-cdn.com/S2212968515000094/1-s2.0-S2212968515000094-main.pdf?_tid=7c92fa40-56e6-11e5-b36a-00000aab0f01&acdnat=1441798543_19612c0d7466780944bc4ae22173da92

  3. Optical phase conjugation in azo-dye doped chiral liquid crystal

    International Nuclear Information System (INIS)

    We report on optical phase conjugation phenomenon observed in chiral nematic liquid crystal showing band gap type Bragg reflection. The phase conjugate to the signal beam is observable only in the small temperature interval when the Bragg condition is fulfilled and only for circularly polarized light. The optical phase conjugation signals were observed at low cw laser light intensities (2, λ = 532 nm). Estimated value of third order optical susceptibility χ(3) = 2.8 × 10-17 m2/V2 is attributed to enhancement due to photoisomerisation of azo-dye (disperse red 1) inducing molecular reorientation process of liquid crystal molecules.

  4. FRET efficiency in surface complexes of CdSe/ZnS quantum dots with azo-dyes

    Science.gov (United States)

    Annas, Kirill I.; Gromova, Yuliya A.; Orlova, Anna O.; Maslov, Vladimir G.; Fedorov, Anatoly V.; Baranov, Alexander V.

    2016-04-01

    Photoinduced dissociation of surface complexes of CdSe/ZnS quantum dots with azo-dye 1-(2- pyridylazo)-2-naphthol (PAN) was investigated. It was shown that the Förster resonance energy transfer contributes in the complexes photodissociation rate, which depends on resonance condition between electronic levels of donor (quantum dots) and acceptor (azo-dye) and donor photoluminescent quantum yield. It has allowed to estimate energy transfer efficiency in the complexes and disclosed a new nonradiative channel that has minor contribution in the deactivation of excited states of quantum dots in the complexes.

  5. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    International Nuclear Information System (INIS)

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone

  6. Case study of the sonochemical decolouration of textile azo dye Reactive Black 5

    Energy Technology Data Exchange (ETDEWEB)

    Vajnhandl, Simona [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)]. E-mail: simona.vajnhandl@uni-mb.si; Le Marechal, Alenka Majcen [University of Maribor, Faculty of Mechanical Engineering, Smetanova 17, 2000 Maribor (Slovenia)

    2007-03-06

    The decolouration and mineralization of reactive dye C.I. Reactive Black 5, a well-known representative of non-biodegradable azo dyes, by means of ultrasonic irradiation at 20, 279 and 817 kHz has been investigated with emphasis on the effect of various parameters on decolouration and degradation efficiency. Characterization of the used ultrasound systems was performed using calorimetric measurements and oxidative species monitoring using Fricke and iodine dosimeter. Experiments were carried out with low frequency probe type, and a high-frequency plate type transducer at 50, 100 and 150 W of acoustic power and within the 5-300 mg/L initial dye concentration range. Decolouration, as well as radical production, increased with increasing frequency, acoustic power, and irradiation time. Any increase in initial dye concentration results in decreased decolouration rates. Sonochemical decolouration was substantially depressed by the addition of 2-methyl-2-propanol as a radical scavenger, which suggests radical-induced reactions in the solution. Acute toxicity to marine bacteria Vibrio fischeri was tested before and after ultrasound irradiation. Under the conditions employed in this study, no toxic compounds were detected after 6 h of irradiation. Mineralization of the dye was followed by TOC measurements. Relatively low degradation efficiency (50% after 6 h of treatment) indicates that ultrasound is rather inefficient in overall degradation, when used alone.

  7. Exploration of redox method for effective removal of vinyl sulphone based reactive azo dye

    International Nuclear Information System (INIS)

    Study depicted here involved the removal of Reactive Red 195 from synthetic wastewater by some oxidizing and reducing agents involving potassium permanganate (KMnO/sub 4/), hydrogen peroxide (H/sub 2/O/sub 2/) ferrioxalate (Fe(OX)) and sodium sulphite (Na/sub 2/SO/sub 3/) under various experimental conditions. In order to get maximum removal of dye some operational factors like pH, initial concentration of dye and concentration of oxidizing and reducing agents were varied. Results indicated that the efficiency of KMnO/sub 4/, H/sub 2/O/sub 2/, Fe(OX) and Na/sub 2/SO/sub 3/ under optimized conditions was 99.31, 49.67, 52 and 46.15 %, respectively, for removal of dye under study. Effectiveness of these redox reagents for the treatment of colored wastewater was also monitored by chemical oxygen demand (COD) and total organic carbon (TOC) content. There was decrease in COD and TOC values after redox treatment which showed chemical decomposition of complex dye molecule. FT-IR examination of products obtained after treatment under optimized experimental conditions also confirmed the chemical degradation of selected reactive azo dye. (author)

  8. Decolorization of azo dyes with Enterobacter agglomerans immobilized in different supports by using fluidized bed bioreactor.

    Science.gov (United States)

    Moutaouakkil, Adnane; Zeroual, Youssef; Dzayri, Fatima Zohra; Talbi, Mohamed; Lee, Kangmin; Blaghen, Mohamed

    2004-02-01

    Immobilized cells of Enterobacter agglomerans, able to reduce azo dyes enzymatically, were used as a biocatalyst for the decolorization of synthetic medium containing the toxic azo dye methyl red (MR). This bacterial strain exhibits high ability to completely decolorize 100 mg/L of MR after only 6 h of incubation under aerobic conditions. Cells of E. agglomerans were immobilized in calcium alginate, polyacylamide, cooper beech, and vermiculite, and were used for the decolorization of MR from synthetic water by using a fluidized bed bioreactor. The highest specific decolorization rate was obtained when E. agglomerans was entrapped in calcium alginate beads and was of about 3.04 mg MR/g cell/h with a 50% conversion time ( t(1/2)) of about 1.6 h. Moreover, immobilized cells in calcium alginate continuously decolorized MR even after seven repeated experiments without significant loss of activity, while polyacrylamide-, cooper beech-, and vermiculite-immobilized cells retained only 62, 15, and 13% of their original activity, respectively. PMID:15057480

  9. 99Tcm-labelling of Evans Blue and three related naphthol-azo dyes

    International Nuclear Information System (INIS)

    Full text: Chemical stability of the naphthol-azo dye Evans Blue (EB) was examined in the presence of acidic stannous chloride (SnCl2) with a view to preparing an instant cold kit. Evans Blue was found to react with this reducing agent, yielding a metal-chelating molecule 1,7-diamino-8-naphthol-2,4-disulfonic acid at high acidity and high stannous concentrations. This reduction reaction was undesirable in the preparation of an EB cold kit. The conditions where reduction was inhibited, required mild acidity (pH 5.0) and a mole ratio of Evans Blue to SnCl2 = [10:1]. Stable cold kits were prepared which were reconstituted with 99Tcm-pertechnetate to result in the desired product with 97.7% radiochemical purity (RCP). Using similar conditions, 99Tcm-Trypan Blue and 99Tcm-Chicago Sky Blue 6B kits were also prepared with 96.4% and 97.6% RCP respectively, but 99Tcm-Amido Black 10B was formed in 69.8% with 24.1%v 99TcmO2 impurity. Based on the radiolabelling efficiencies of chosen model compounds, it was deduced that 99Tcm metal predominantly coordinated with the l-amino-8-hydroxy groups in the molecular structure of Evans Blue and the other naphthol-azo dyes to form their respective 99Tcm-complexes. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  10. Microbial dynamics during azo dye degradation in a UASB reactor supplied with yeast extract

    Science.gov (United States)

    Silva, S.Q.; Silva, D.C.; Lanna, M.C.S.; Baeta, B.E.L.; Aquino, S.F.

    2014-01-01

    The present work aimed to investigate the microbial dynamics during the anaerobic treatment of the azo dye blue HRFL in bench scale upflow anaerobic sludge bed (UASB) reactor operated at ambient temperature. Sludge samples were collected under distinct operational phases, when the reactor were stable (low variation of color removal), to assess the effect of glucose and yeast extract as source of carbon and redox mediators, respectively. Reactors performance was evaluated based on COD (chemical oxygen demand) and color removal. The microbial dynamics were investigated by PCR-DGGE (Polimerase Chain Reaction - Denaturing Gradient of Gel Electrophoresis) technique by comparing the 16S rDNA profiles among samples. The results suggest that the composition of microorganisms changed from the beginning to the end of the reactor operation, probably in response to the presence of azo dye and/or its degradation byproducts. Despite the highest efficiency of color removal was observed in the presence of 500 mg/L of yeast extract (up to 93%), there were no differences regarding the microbial profiles that could indicate a microbial selection by the yeast extract addition. On the other hand Methosarcina barkeri was detected only in the end of operation when the best efficiencies on color removal occurred. Nevertheless the biomass selection observed in the last stages of UASB operation is probably a result of the washout of the sludge in response of accumulation of aromatic amines which led to tolerant and very active biomass that contributed to high efficiencies on color removal. PMID:25763018

  11. Synthesis and Evaluation of Changes Induced by Solvent and Substituent in Electronic Absorption Spectra of New Azo Disperse Dyes Containig Barbiturate Ring

    OpenAIRE

    Hooshang Hamidian; Najmeh Zahedian; Dadkhoda Ghazanfari; Samieh Fozooni

    2013-01-01

    Six azo disperse dyes were prepared by diazotizing 4-amino hippuric acid and coupled with barbituric acid and 2-thiobarbituric acid. Then, the products were reacted with aromatic aldehyde, sodium acetate, and acetic anhydride, and oxazolone derivatives were formed. Characterization of the dyes was carried out by using UV-Vis, FT-IR, 1H NMR and 13C NMR, and mass spectroscopic techniques. The solvatochromic behavior of azo disperse dyes was evaluated in various solvents. The effects of substitu...

  12. An Improved Method for Removal of Azo Dye Orange II from Textile Effluent Using Albumin as Sorbent

    OpenAIRE

    Tadashi Ohashi; Alícia M. T. Jara; Anabelle C. L. Batista; Franco, Luciana O.; Marcos A. Barbosa Lima; Mohand Benachour; Carlos A. Alves da Silva; Galba M. Campos-Takaki

    2012-01-01

    Azo dyes are generally resistant to biodegradation due to their complex structures. Acid orange II is one of the most widely used dyes in the textile industry. The influence of bovine serum albumin (BSA) in different concentrations, pH, and time of contact on Orange II was investigated using kinetics and adsorption-isotherm experiments. The results showed that the maximum colour removed from dye/albumin was 99.50% and that a stable dye-protein complex had been formed at pH 3.5 and in a propor...

  13. Degradation of industrial azo dye in aqueous solution by heterogeneous Fenton process (fly ash/H2O2)

    OpenAIRE

    Bečelić-Tomin Milena R.; Dalmacija Milena B.; Dalmacija Božo D.; Rajić Ljiljana M.; Tomašević Dragana D.

    2012-01-01

    The aim of this study was to investigate the possibilities and efficiency of heterogeneous Fenton process with the use of fly ash from thermal power plants Kolubara, Serbia, as the catalyst in the degradation of industrial azo dye Zetanyl Rosso B-NG. The effects of various experimental parameters such as pH, temperature, concentration of fly ash, the initial concentration of H2O2 and initial concentration of dye on the kinetics and efficiency of decolorization were investigated. Simulta...

  14. Enhanced bio-decolorization of azo dyes by co-immobilized quinone-reducing consortium and anthraquinone

    DEFF Research Database (Denmark)

    Su, YY; Zhang, Yifeng; Wang, J;

    2009-01-01

    exhibited good catalytic activity and increased the decolorization rate for many kinds of azo dyes. The reusability of the co-immobilized beads was evaluated with repeated-batch decolorization experiments. After ten repeated experiments, the decolorization rate of co-immobilized beads retained over 92.8% of...

  15. Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase

    Institute of Scientific and Technical Information of China (English)

    Nabila Boucherit; Mahmoud Abouseoud; Lydia Adour

    2013-01-01

    Enzymatic decolourization of the azo dye,Direct Yellow (DY 106) by Cucurbita pepo (courgette) peroxidase (CP) is a complex process,which is greatly affected by pH,temperature,enzyme activity and the concentrations of H2O2 and dye.Courgette peroxidase was extracted and its performance was evaluated by using the free-CP (FCP) and immobilized-CP (ICP) forms in the decolourization of DY106.Immobilization of peroxidase in calcium alginate beads was performed according to a strategy aiming to minimize enzyme leakage and keep its activity at a maximum value by optimizing sodium alginate content,enzyme loading and calcium chloride concentration.The initial conditions it which the highest DY106 decolourization yield was obtained were found at pH 2,temperature 20C,H2O2 dose 1 mmol]L (FCP) and 100 mmol/L (ICP).The highest decolourization rates were obtained for dye concentrations 50 mg/L (FCP) and 80 mg/L (ICP).Under optimal conditions,the FCP was able to decolorize more than 87% of the dye within 2 min.While with ICP,the decolourization yield was 75% within 15 min.The decolourization and removal of DY106 was proved by UV-Vis analysis.Fourier transform infrared (FT-IR) spectroscopy analysis was also performed on DY106 and enzymatic treatment precipitated byproduct.

  16. Synthesis of MoO{sub 3} nanoparticles for azo dye degradation by catalytic ozonation

    Energy Technology Data Exchange (ETDEWEB)

    Manivel, Arumugam; Lee, Gang-Juan [Department of Environmental Engineering and Science, Feng Chia University, Taiwan (China); Chen, Chin-Yi [Department of Material Science and Engineering, Feng Chia University, Taiwan (China); Chen, Jing-Heng; Ma, Shih-Hsin [Department of Photonics, Feng Chia University, Taiwan (China); Horng, Tzzy-Leng [Department of Applied Mathematics, Taiwan (China); Wu, Jerry J., E-mail: jjwu@fcu.edu.tw [Department of Environmental Engineering and Science, Feng Chia University, Taiwan (China)

    2015-02-15

    Highlights: • Synthesis of one-dimensional MoO{sub 3} nanostructures using hydrothermal, microwave, and sonochemical methods. • Sonochemical synthesized MoO{sub 3} presents the best efficiency for the dye removal by catalytic ozonation. • Efficient environmental remediation process. - Abstract: One-dimensional molybdenum trioxide nanostructures were prepared in three different approaches, including thermal, microwave, and sonochemical methods. The physicochemical properties of the obtained MoO{sub 3} nanoparticles were investigated by diffused reflectance spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Brunauer–Emmett–Teller surface area analysis. Among the methods as investigated, sonochemical synthesis gave well-dispersed fine MoO{sub 3} nanoparticles compared with the other approaches. All the synthesized MoO{sub 3} nanostructures were examined for the catalytic ozonation to degrade azo dye in aqueous environment. Different performances were obtained for the catalyst prepared in different methods and the catalytic efficiencies were found to be the order of sonochemical, microwave, and then thermal methods. The sonochemical MoO{sub 3} catalyst allowed the total dye removal within 20 min and its good performance was justified according to their higher surface area with higher number of active sites that provide effective dye interaction for better degradation.

  17. Synthesis of MoO3 nanoparticles for azo dye degradation by catalytic ozonation

    International Nuclear Information System (INIS)

    Highlights: • Synthesis of one-dimensional MoO3 nanostructures using hydrothermal, microwave, and sonochemical methods. • Sonochemical synthesized MoO3 presents the best efficiency for the dye removal by catalytic ozonation. • Efficient environmental remediation process. - Abstract: One-dimensional molybdenum trioxide nanostructures were prepared in three different approaches, including thermal, microwave, and sonochemical methods. The physicochemical properties of the obtained MoO3 nanoparticles were investigated by diffused reflectance spectroscopy, X-ray diffraction analysis, field emission scanning electron microscopy, high resolution transmission electron microscopy, and Brunauer–Emmett–Teller surface area analysis. Among the methods as investigated, sonochemical synthesis gave well-dispersed fine MoO3 nanoparticles compared with the other approaches. All the synthesized MoO3 nanostructures were examined for the catalytic ozonation to degrade azo dye in aqueous environment. Different performances were obtained for the catalyst prepared in different methods and the catalytic efficiencies were found to be the order of sonochemical, microwave, and then thermal methods. The sonochemical MoO3 catalyst allowed the total dye removal within 20 min and its good performance was justified according to their higher surface area with higher number of active sites that provide effective dye interaction for better degradation

  18. Synthesis and application of p-tert-butylcalix[8]arene immobilized material for the removal of azo dyes

    International Nuclear Information System (INIS)

    Graphical abstract: The sorption of selected azo dyes is highly pH dependent and newly immobilized material 4 is potentially more effective sorbent as compared to pure silica (1) as well as p-tert-butylcalix[8]arene (3). Research highlights: → Sorption behavior investigation of p-tert-butyl-calix[8]arene immobilized material4. → Azo dyes (i.e. RB-5 and RR-45) were used as sorbate. → Optimization of different parameters to evaluate sorption performance of material 4. → Sorption efficiency of resin 4 for RB-5 and RR-45 azo dyes is highly pH dependent. → The sorption data was evaluated by sorption isotherms. - Abstract: The present study describes synthesis of a new resin through immobilization of p-tert-butylcalix[8]arene onto silica and its application for the removal of azo dyes from aqueous media as well as from textile effluents. The newly synthesized material 4 is characterized by FT-IR spectroscopy, scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Reactive Black-5 (RB-5) and Reactive Red-45 (RR-45) azo dyes were used as sorbate. Batch wise sorption experiments were conducted to optimize various experimental parameters such as the effect of sorbent dosage, electrolyte, pH, dye concentration, and contact time. The optimized pH for the effective removal of RB-5 and RR-45 dyes was 9 and 3, respectively. The increase in material 4 dosage increased the percent sorption. Both Langmuir and Freundlich isotherm models were applied to experimental data and Langmuir isotherm model found to be best fit. The results revealed that material 4 was potentially more effective sorbent for the sorption of selected azo dyes as compared to pure silica and p-tert-butylcalix[8]arene. The field studies also supported the effectiveness of material 4, which could be useful for the removal of both the dyes and also for the normalization of pH, TDS, conductivity and salinity near to the drinking water.

  19. Mechanism of azo dye degradation by ionizing radiation. Degradation of sulfanilic acid azochromotrop and its parent compounds in aqueous solution

    International Nuclear Information System (INIS)

    Complete text of publication follows. Mechanistic studies were made on ·OH radical and hydrated electron reaction with Sulfanilic Acid Azochromotrop (SPADNS) as model azo dye. SPADNS contains 4,5-dihydroxynaphtalene 2,7-disulfonic acid part and 4-sulfophenylazo group. To establish the details of the reaction mechanism the reactions of two simpler molecules without 4-sulfophenylazo part were also studied: one of them contained one (in position 4, II), the other two (in positions 4 and 5, III) -OH groups. ·OH radicals react with these molecules with radical addition to the naphthalene 2,7-disulfonic acid part. The adduct cyclohexadienyl type radical may decay in radical-radical reactions, or undergoes a (pH dependent) water elimination to naphthoxy radical, radical decay takes place on the ms timescale. ·OH radical addition on the azo bond in dyes has low importance. Degradation efficiencies are 0.6-0.8. The hydrated electron in the case of the two simpler molecules reacts with the rings, while in the case of dye with the azo bond. Electron scavenging is followed by protonation, this reaction in the case of II and III yields cyclohexadienyl, while with the dye hydrazo radical. The efficiency of degradation with II and III is 0.2-0.6, while for the dye it is close to 1.

  20. High-throughput determination of Sudan Azo-dyes within powdered chili pepper by paper spray mass spectrometry.

    Science.gov (United States)

    Taverna, Domenico; Di Donna, Leonardo; Mazzotti, Fabio; Policicchio, Barbara; Sindona, Giovanni

    2013-05-01

    A high-throughput mass spectrometric method is presented for the simultaneous detection of Sudan I, II, III, IV and Para-Red azo-dyes in foodstuff. The method is based on the use of paper spray mass spectrometry (MS) and deuterium-labeled internal standards on a triple-quadrupole instrument. A detailed assay of each azo-dye was performed by the isotope dilution method, through the precursor ion scan approach, using deuterium-labeled internal standards. The gas-phase breakdown pattern of each labeled and unlabeled analogue displays the naphthoic moiety as a common fragment. Sudan dyes can be determined above the threshold of 1 ppm. Paper spray allows for a wide range of analytes and samples to be investigated by MS in the open air and without sample preparation and bypassing chromatography. PMID:23674278

  1. Kinetic and equilibrium study of adsorption of di-azo dyes on commercial activated carbon

    International Nuclear Information System (INIS)

    This research work is concerned with studying the adsorption of a number of di-azo dyes on commercial activated carbon (CAC). The synthesized dyes vary in their structures by the central parts. which are either ortho, meta or para phenvlene diamine. This variation affects the linearity of molecules, their spatial arrangement and electron movement throughout the molecule by resonance. Factors a fleeting adsorption process, such as the efiect of contact time, initial concentration, p1-I of the adsorption medium, adsorbent dose, effect of solvent and temperature were studied. The results indicated that, the adsorption process is fast in the first 10 mm, then gradually decreased with time and approaches maximum within 70-80 min for all the studied dyes. The increase of initial concentration and temperature decreased the adsorption efficiency. The results also shows that, the adsorption is found to be more efficient at low Ph value. The increase of the adsorbent dose increases the adsorption efficiency and decreases its capacity. The variation of solvent (ethanol-water ratio) indicates that the decrease of dielectric constant lowers the adsorption efficiency. The study included application of three adsorption isotherms, Freundlich, Langmuir and Tempkin on the experimental data of the studied systems. The results indicated that, Freundlich isotherm fits better the adsorption data. Kinetic analysis of the adsorption data was also conducted by employing 4 kinetic models; pseudo first order and pseudo second order, Elovich and intra particle diffusion equations. The results obtained conclude that, the studied systems follow the Pseudo second order model. (author)

  2. Enzyme-mediated bacterial biodegradation of an azo dye (C.I. Acid blue 113): reuse of treated dye wastewater in post-tanning operations.

    Science.gov (United States)

    Senthilvelan, T; Kanagaraj, J; Panda, R C

    2014-11-01

    "Dyeing" is a common practice used to color the hides during the post-tanning operations in leather processing generating plenty of wastewater. The waste stream containing dye as pollutant is severely harmful to living beings. An azo dye (C.I. Acid Blue 113) has been biodegraded effectively by bacterial culture mediated with azoreductase enzyme to reduce the pollution load in the present investigation. The maximum rate of dye degradation was found to be 96 ± 4 and 92 ± 4 % for the initial concentrations of 100 and 200 mg/l, respectively. The enzyme activity was measured using NADH as a substrate. Fourier transform infrared spectroscopy (FT-IR) analysis was confirmed that the transformation of azo linkage could be transformed into N2 or NH3 or incorporated into complete biomass. Breaking down of dye molecules to various metabolites (such as aniline, naphthalene-1,4-diamine, 3-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid, 8-aminonaphthalene-1-sulfonic acid, 5,8-diaminonaphthalene-1-sulfonic acid) was confirmed by gas chromatography and mass spectra (GC-MS) and mass (electrospray ionization (ESI)) spectra analysis. The treated wastewater could be reused for dyeing operation in the leather processing, and the properties of produced leather were evaluated by conventional methods that revealed to have improved dye penetration into the grain layer of experimental leather sample and resulted in high levelness of dyeing, which helps to obtain the desired smoothness and soft leather properties. PMID:25163883

  3. Synthesis and characterization of Mg-based amorphous alloys and their use for decolorization of Azo dyes

    International Nuclear Information System (INIS)

    Mg-based alloys are light weight and have wide range of applications in the automotive industry. These alloys are widely used because of their very attractive physical and mechanical properties and corrosion resistance. The properties and applications can be further improved by changing the nature of materials from crystalline to amorphous. In this study, melt spun ribbons (MSRs) of Mg70Zn25Ca5 Mg68Zn27Ca5 alloys were prepared by melt spinning technique by using 3-4N pure metals. Characterization of the samples was done by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and energy dispersive x-ray analyzer (EDAX). Microstructural investigations were conducted by using scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as optical and stereo scan microscopy techniques. DSC results showed multistage crystallization. Activation energy was found to be 225 kJ/mol by Kissinger method indicating good thermal stability against crystallization. XRD, DSC, SEM and EDS (energy dispersive spectroscopy) results are agreed very well. In order to study decolorization, the MSRs of Mg70Zn25Ca5 Mg68Zn27Ca5 alloys were treated repeatedly with various azo dyes at room temperature. In order to compare the results, MSRs of amorphous Zr- and Ni-based metallic glasses were also treated. Reaction of MSRs with azo dyes results in their decolorization in a few hours. Decolorization of azo dyes takes place by introducing amorphous MSRs which results in breaking the -N=N- bonds that exist in dye contents. It is concluded that Mg-based alloys are useful for paint and dye industries and will be beneficial to control water pollution. Comparison of results showed that Mg-based alloys are more efficient than Zr- and Ni-based amorphous alloys for decolorization of azo dyes

  4. Synthesis and characterization of Mg-based amorphous alloys and their use for decolorization of Azo dyes

    International Nuclear Information System (INIS)

    Mg-based alloys are light weight and have wide range of applications in the automotive industry. These alloys are widely used because of their very attractive physical and mechanical properties and corrosion resistance. The properties and applications can be further improved by changing the nature of materials from crystalline to amorphous. In this study, melt spun ribbons (MSRs) of Mg/sub 70/Zn/sub 25/Ca/sub 5/ Mg/sub 68/Zn/sub 27/Ca/sub 5/ alloys were prepared by melt spinning technique by using 3-4N pure metals. Characterization of the samples was done by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and energy dispersive x-ray analyzer (EDAX). Microstructural investigations were conducted by using scanning electron microscopy (SEM), atomic force microscopy (AFM) as well as optical and stereo scan microscopy techniques. DSC results showed multistage crystallization. Activation energy was found to be 225 kJ/mol by Kissinger method indicating good thermal stability against crystallization. XRD, DSC, SEM and EDS (energy dispersive spectroscopy) results are agreed very well. In order to study decolorization, the MSRs of Mg/sub 70/Zn/sub 25/Ca/sub 5/ Mg/sub 68/Zn/sub 27/Ca/sub 5/ alloys were treated repeatedly with various azo dyes at room temperature. In order to compare the results, MSRs of amorphous Zr- and Ni-based metallic glasses were also treated. Reaction of MSRs with azo dyes results in their decolorization in a few hours. Decolorization of azo dyes takes place by introducing amorphous MSRs which results in breaking the -N=N- bonds that exist in dye contents. It is concluded that Mg-based alloys are useful for paint and dye industries and will be beneficial to control water pollution. Comparison of results showed that Mg-based alloys are more efficient than Zr- and Ni-based amorphous alloys for decolorization of azo dyes. (author)

  5. Holographic gratings recorded in poly(lactic acid)/azo-dye films

    Science.gov (United States)

    Cambiasso, Javier; Goyanes, Silvia; Ledesma, Silvia

    2015-09-01

    Diffraction gratings were recorded in biodegradable polymer films of poly(lactic acid) doped with the photoisomerisable azo-dye (Disperse Orange 3). It is shown that the diffraction efficiency of the recorded grating can be improved by 220% via an all-optical treatment. This all-optical treatment consists of a pre-irradiation of the sample with the writing laser beam at high power during a short period of time, preventing damage of the material, followed by a much longer inscription at relatively low power. Furthermore, it is shown that the addition of a small amount of 0.05 wt% of multi-walled carbon nanotubes to the photoresponsive polymer increases the maximum diffraction efficiency as well as the remanent efficiency by 20%. Finally, this last photoresponsive nano-composite is also sensitive to the pre-irradiation treatment.

  6. Degradation of commercial azo dye reactive Black B in photo/ferrioxalate system

    International Nuclear Information System (INIS)

    The photolysis and photo-catalysis of ferrioxalate in the presence of hydrogen peroxide with UV irradiation (UV/ferrioxalate/H2O2 process) for treating the commercial azo dye, reactive Black B (RBB), is examined. An effort is made to decolorize textile effluents at near neutral pH for suitable discharge of waste water. pH value, light source, type of initial catalyst (Fe3+ or Fe2+) and concentration of oxalic acid (Ox) strongly affected the RBB removal efficiency. The degradation rate of RBB increased as pH or the wavelength of light declined. The optimal molar ratio of oxalic acid to Fe(III) is three, and complete color removal is achieved at pH 5 in 2 h of the reaction. Applying oxalate in such a photo process increases both the RBB removal efficiency and the COD removal from 68% and 21% to 99.8% and 71%, respectively

  7. Anion recognition ability of a novel azo dye derived from 4-hydroxycoumarin

    International Nuclear Information System (INIS)

    The anion recognition ability of a novel azo dye derived from 4-hydroxycuomarin (L) was investigated by experimental (UV–vis, fluorescence and 1H NMR) and theoretical [(B3LYP/6-31G(d,p)] methods. Among the surveyed anions, the receptor L showed both naked-eye detectable color and spectral changes in the presence of F−, AcO− and H2PO4− due to the formation of hydrogen bonding complexes followed by deprotonation between these anions and L. - Highlights: • Anion recognition ability of an easy-to-prepare coumarin derivative L was reported. • L showed both naked-eye and spectral responses towards AcO−, F− and H2PO4−. • Deprotonation mechanism was proposed for the observed spectral responses. • L showed selective ratiometric fluorescence ‘turn-on’ responses towards AcO− and F−

  8. Direct laser interference patterning of polystyrene films doped with azo dyes, using 355 nm laser light

    International Nuclear Information System (INIS)

    Highlights: • We describe the first use of Direct Laser Interference Patterning on PS at 355 nm. . • The structured areas of regular lines are produced in several square millimeters. • The method, Direct Laser Interference Patterning (DLIP) uses a single laser pulse. • DLIP is applied at room temperature and atmospheric pressure. • DLIP is easier to use than other lithographic techniques. • The topography contrasts with the usual Polystyrene ablation at lower wavelengths. - Abstract: The generation of line-like periodic patterns by direct laser interference patterning (DLIP) of polystyrene films (PS) at a wavelength of 355 nm has been investigated. No structuration is achieved in plain PS due to the weak absorption of the polymer at 355 nm. On the other hand, patterning is achieved on films doped (PSd) with an azo dye (2-anisidine → 2-anisidine) which is incorporated in the polymer solution used for film preparation. Periodic micro-structures are generated. DLIP on PSd results in the swelling of the surface at low fluences, while at high laser intensities it causes the ablation of the regions at the interference maxima positions. The results contrast with the usual process of DLIP on PS (at shorter wavelengths, like 266 nm) where only ablation is detected. The results suggest that decomposition of the azo dye is the driving force of the patterning which therefore differ from the patterning obtained when plain PS is irradiated with laser light able to be absorbed by the aromatic ring in PS (e.g. 266 nm). The biocompatibility of these materials and adhesion of cells was tested, the data from in vitro assays shows that fibroblast cells are attached and proliferate extensively on the PSd films

  9. All optical controlled photonic integrated circuits using azo dye functionized sol-gel material

    Science.gov (United States)

    Ke, Xianjun

    The main focus of this dissertation is development and characterization of all-optical controllable azo dye functionized sol gel material, demonstrating a PIC fabrication technique on glass substrate using such material, and exploration and feasibility demonstration of three PIC functional devices namely optical variable attenuator, optical switches, and optical tunable filters using the material. The realization of all the devices in this dissertation are based on one material: dye functionalized sol-gel material. A photochromic sol-gel material functionalized with azo dye was synthesized and characterized. It possesses a photochromic characteristic under the control of green laser beam illumination. The material characteristics suggest the possibility of a new promising material platform candidate for the fabrication of alloptical controlled photonic integrated circuits. As the first potential application of the dye functionalized sol-gel material, an alloptical variable attenuator was designed and demonstrated. The optical variable attenuation is achieved in Mach-Zehnder interferometric configuration through all-optical modulation of sol-gel waveguide phase shifters. A 2 x 2 optical switch based on multimode interference (MMI) waveguide structure is proposed in the dissertation. The schematic configuration of the optical switch consists of a cascade of two identical MMIs with two all-optical controlled phase shifters realized by using the photochromic sol-gel material. The cross or bar switch state of the optical switch is determined by the phase difference between the two sol-gel waveguide phase shifters. An all-optical tunable filter is designed and its feasibility demonstrated by using the sol-gel photochromic material. Except for the phase change demonstrated on sol-gel waveguide phase shifters, dynamic gratings were observed on sol-gel film when exposed to two interference beams. This reveals the possibility of realizing Bragg grating-based tunable filters

  10. Design, synthesis and evaluation of redox, second order nonlinear optical properties and theoretical DFT studies of novel bithiophene azo dyes functionalized with thiadiazole acceptor groups

    OpenAIRE

    Castro, M. Cidália R.; Schellenberg, Peter Michael; Belsley, M.; Fernandes, Sara S. M.; Raposo, M. Manuela M.

    2012-01-01

    Two series of novel thermally stable second-order nonlinear optical (NLO) heterocyclic azo dyes 4-5 have been designed and synthesized. The two series of compounds were based on different combinations of acceptor groups (thiadiazole or arylthiadiazole electron-deficient heterocycles) linked to bithiophene which acts at the same time as a donor group and as a pi-conjugated bridge. The solvatochromic behavior of azo dyes 4-5 was investigated in several solvents of different polarity, while thei...

  11. Azo dye degradation by Phanerochaete chrysosporium in the medium enriched with nitrogen in the presence of primary co-substrate

    Directory of Open Access Journals (Sweden)

    Marcus Vinicius Freire Andrade

    2013-10-01

    Full Text Available This work sought to evaluate the ability of fungi Phanerochaete chryosporium to degrade congo red azo dye in batch reactor, evaluate the influence of glucose and wheat bran as co-substrates on the removal of the dye in the medium and investigate the influence of ammonium chloride, ammonium nitrate and ammonium sulfate as the inorganic nitrogen source for the process. Wheat bran was not effective satisfactorily for the removal of dye and organic matter had no desired effect for the removal of color and organic matter and showed the lowest values of k2, 0.008 M-1.d-1and 0.0004 M-1.d-1, respectively. Glucose presented the best response with the highest final percentage of dye removal (97% and rate of dye removal (0.017 M-1.d-1, without adding an external source of nitrogen.

  12. Synthesis and Evaluation of Changes Induced by Solvent and Substituent in Electronic Absorption Spectra of New Azo Disperse Dyes Containig Barbiturate Ring

    Directory of Open Access Journals (Sweden)

    Hooshang Hamidian

    2013-01-01

    Full Text Available Six azo disperse dyes were prepared by diazotizing 4-amino hippuric acid and coupled with barbituric acid and 2-thiobarbituric acid. Then, the products were reacted with aromatic aldehyde, sodium acetate, and acetic anhydride, and oxazolone derivatives were formed. Characterization of the dyes was carried out by using UV-Vis, FT-IR, 1H NMR and 13C NMR, and mass spectroscopic techniques. The solvatochromic behavior of azo disperse dyes was evaluated in various solvents. The effects of substituents of aromatic aldehyde, barbiturate, and thiobarbiturate ring on the color of dyes were investigated.

  13. Fe3O4@Nico-Ag magnetically recyclable nanocatalyst for azo dyes reduction

    Science.gov (United States)

    Kurtan, U.; Amir, Md.; Baykal, A.

    2016-02-01

    In this study, we report the successful synthesis of Fe3O4@Nico-Ag nanocomposite as magnetically recyclable nanocatalyst (MRCs) via reflux process at 80 °C for 5 h followed by reduction of Ag+. FeCl3·6H2O, FeCl2·4H2O, AgNO3 as starting reactants and nicotinic acid as linker. The structure, morphology, thermal behaviour and magnetic properties of the product were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometry (EDX), thermal gravimetry (TG) and vibrating sample magnetometry (VSM), respectively. The catalytic activity of product for various azo dyes such as methylene blue (MB), methyl orange (MO), Rhodamine B (RhB) and eosin Y (EY) and their double mixtures were studied. It was found that Fe3O4@Nico-Ag MRCs is an efficient catalyst and can also rapidly separated from the reaction medium using magnet without considerable loss in its catalytic activity and used several times. Fe3O4@Nico-Ag MRCs has potential for the treatment of industrial dye pollutants.

  14. Treatment of Sulfonated Azo Dye Reactive Red 198 by UV/H2O2

    Directory of Open Access Journals (Sweden)

    Jefferson P. Ribeiro

    2014-01-01

    Full Text Available UV/H2O2 system was tested on the color removal of sulfonated azo dye Reactive Red 198 (RR, which is widely used in textile process. The effects of hydrogen peroxide concentration, temperature, pH, and the in-line addition of hydrogen peroxide on high color and chemical oxygen demand (COD removals were investigated. The kinetic of dye decolorization was also determined. The results showed that 2% H2O2 decreased the process efficiency, while 1% H2O2 solution led to a better performance of the system. Despite the fact that the pH increase had small effect on color removal, it affects positively COD removals. The same behavior was found for temperature increase. A high temperature resulted in a slight decrease in color removal and a sharp decrease for COD removal. In addition the H2O2 in-line provided a small improvement in both color and COD removals. UV/1% H2O2 treatment was the most efficient, the good performance was linked to higher amount of hydroxyl radicals formed.

  15. Optimization of integrated chemical-biological degradation of a reactive azo dye using response surface methodology

    International Nuclear Information System (INIS)

    The integrated chemical-biological degradation combining advanced oxidation by UV/H2O2 followed by aerobic biodegradation was used to degrade C.I. Reactive Azo Red 195A, commonly used in the textile industry in Australia. An experimental design based on the response surface method was applied to evaluate the interactive effects of influencing factors (UV irradiation time, initial hydrogen peroxide dosage and recirculation ratio of the system) on decolourisation efficiency and optimizing the operating conditions of the treatment process. The effects were determined by the measurement of dye concentration and soluble chemical oxygen demand (S-COD). The results showed that the dye and S-COD removal were affected by all factors individually and interactively. Maximal colour degradation performance was predicted, and experimentally validated, with no recirculation, 30 min UV irradiation and 500 mg H2O2/L. The model predictions for colour removal, based on a three-factor/five-level Box-Wilson central composite design and the response surface method analysis, were found to be very close to additional experimental results obtained under near optimal conditions. This demonstrates the benefits of this approach in achieving good predictions while minimising the number of experiments required

  16. A highly efficient single chambered up-flow membrane-less microbial fuel cell for treatment of azo dye Acid Orange 7-containing wastewater.

    Science.gov (United States)

    Thung, Wei-Eng; Ong, Soon-An; Ho, Li-Ngee; Wong, Yee-Shian; Ridwan, Fahmi; Oon, Yoong-Ling; Oon, Yoong-Sin; Lehl, Harvinder Kaur

    2015-12-01

    Single chambered up-flow membrane-less microbial fuel cell (UFML MFC) was developed to study the feasibility of the bioreactor for decolorization of Acid Orange 7 (AO7) and electricity generation simultaneously. The performance of UFML MFC was evaluated in terms of voltage output, chemical oxygen demand (COD) and color removal efficiency by varying the concentration of AO7 in synthetic wastewater. The results shown the voltage generation and COD removal efficiency decreased as the initial AO7 concentration increased; this indicates there is electron competition between anode and azo dye. Furthermore, there was a phenomenon of further decolorization at cathode region which indicates the oxygen and azo dye are both compete as electron acceptor. Based on the UV-visible spectra analysis, the breakdown of the azo bond and naphthalene compound in AO7 were confirmed. These findings show the capability of integrated UFML MFC in azo dye wastewater treatment and simultaneous electricity generation. PMID:26342340

  17. Application of acidic treated pumice as an adsorbent for the removal of azo dye from aqueous solutions: kinetic, equilibrium and thermodynamic studies

    OpenAIRE

    Saied Bashiri; Gholam Hossein Safari; Abdeltif Amrane; Mohammad Noori Sepehr; Mansur Zarrabi; Mohammad Reza Samarghandi

    2012-01-01

    Abstract Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as an efficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the e...

  18. A New Photocatalytic System Using Steel Mesh and Cold Cathode Fluorescent Light for the Decolorization of Azo Dye Orange G

    OpenAIRE

    Ming-Chin Chang; Chin-Pao Huang; Hung-Yee Shu; Yung-Chen Chang

    2012-01-01

    High color and organic composition, the effluents from the textile dyeing and finishing industry, can be treated by photocatalytic oxidation with UV/TiO2. The objective of this study was to prepare a new photocatalytic system by coating nanosized TiO2 particles on steel mesh support and using cold cathode fluorescent light (CCFL) irradiation at 365 nm in a closed reactor for the oxidation of azo dye C.I. Orange G (OG). Various factors such as reaction time, coating temperature, TiO2 dosage, p...

  19. Colour removal from aqueous solutions of metal-complex azo dyes using bacterial cells of Shewanella strain J18 143.

    Science.gov (United States)

    Li, Tie; Guthrie, James Thomas

    2010-06-01

    The decoloration treatment of textile dye effluents through biodegradation, using bacterial cells, has been studied as a possible means of solving some of the problems that are associated with the pollution of water sources by colorants. In this paper, the use of whole bacterial cells of Shewanella J18 143 for the reduction of aqueous solutions of selected mono-azo, metal-complex dyes, namely Irgalan Grey GLN, Irgalan Black RBLN and Irgalan Blue 3GL, was investigated. The effects of temperature, pH and dye concentration on colour removal were also investigated and shown to be important. The operative conditions for the removal of colour were 30 degrees C, at pH 6.8, with a final dye concentration of 0.12 g/L in the colour reduction system. This study provides an extension to the application of Shewanella strain J18 143 bacterial cells in the decoloration of textile wastewaters. PMID:20167478

  20. Conducting polypyrrole films as a potential tool for electrochemical treatment of azo dyes in textile wastewaters

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Mominul [Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109 (Australia); Smith, Warren T. [Samadha Pacifica Pty Ltd, Woonona, NSW 2517 (Australia); Wong, Danny K.Y., E-mail: Danny.Wong@mq.edu.au [Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109 (Australia)

    2015-02-11

    Highlights: • Anion exchange property of polypyrrole films exploited in developing a treatment method for Acid Red 1. • An environmentally friendly treatment method for Acid Red 1 without generating any toxic by-products. • Acid Red 1 is anodically entrapped and cathodically liberated at polypyrrole films. • Analytical characteristics of Acid Red 1-entrapped polypyrrole films. - Abstract: In this paper, we demonstrate conducting polypyrrole films as a potential green technology for electrochemical treatment of azo dyes in wastewaters using Acid Red 1 as a model analyte. These films were synthesised by anodically polymerising pyrrole in the presence of Acid Red 1 as a supporting electrolyte. In this way, the anionic Acid Red 1 is electrostatically attracted to the cationic polypyrrole backbone formed to maintain electroneutrality, and is thus entrapped in the film. These Acid Red 1-entrapped polypyrrole films were characterised by electrochemical, microscopic and spectroscopic techniques. Based on a two-level factorial design, the solution pH, Acid Red 1 concentration and polymerisation duration were identified as significant parameters affecting the entrapment efficiency. The entrapment process will potentially aid in decolourising Acid Red 1-containing wastewaters. Similarly, in a cathodic process, electrons are supplied to neutralise the polypyrrole backbone, liberating Acid Red 1 into a solution. In this work, following an entrapment duration of 480 min in 2000 mg L{sup −1} Acid Red 1, we estimated 21% of the dye was liberated after a reduction period of 240 min. This allows the recovery of Acid Red 1 for recycling purposes. A distinctive advantage of this electrochemical Acid Red 1 treatment, compared to many other techniques, is that no known toxic by-products are generated in the treatment. Therefore, conducting polypyrrole films can potentially be applied as an environmentally friendly treatment method for textile effluents.

  1. Conducting polypyrrole films as a potential tool for electrochemical treatment of azo dyes in textile wastewaters

    International Nuclear Information System (INIS)

    Highlights: • Anion exchange property of polypyrrole films exploited in developing a treatment method for Acid Red 1. • An environmentally friendly treatment method for Acid Red 1 without generating any toxic by-products. • Acid Red 1 is anodically entrapped and cathodically liberated at polypyrrole films. • Analytical characteristics of Acid Red 1-entrapped polypyrrole films. - Abstract: In this paper, we demonstrate conducting polypyrrole films as a potential green technology for electrochemical treatment of azo dyes in wastewaters using Acid Red 1 as a model analyte. These films were synthesised by anodically polymerising pyrrole in the presence of Acid Red 1 as a supporting electrolyte. In this way, the anionic Acid Red 1 is electrostatically attracted to the cationic polypyrrole backbone formed to maintain electroneutrality, and is thus entrapped in the film. These Acid Red 1-entrapped polypyrrole films were characterised by electrochemical, microscopic and spectroscopic techniques. Based on a two-level factorial design, the solution pH, Acid Red 1 concentration and polymerisation duration were identified as significant parameters affecting the entrapment efficiency. The entrapment process will potentially aid in decolourising Acid Red 1-containing wastewaters. Similarly, in a cathodic process, electrons are supplied to neutralise the polypyrrole backbone, liberating Acid Red 1 into a solution. In this work, following an entrapment duration of 480 min in 2000 mg L−1 Acid Red 1, we estimated 21% of the dye was liberated after a reduction period of 240 min. This allows the recovery of Acid Red 1 for recycling purposes. A distinctive advantage of this electrochemical Acid Red 1 treatment, compared to many other techniques, is that no known toxic by-products are generated in the treatment. Therefore, conducting polypyrrole films can potentially be applied as an environmentally friendly treatment method for textile effluents

  2. Photo-Fenton-like degradation of azo dye methyl orange using synthetic ammonium and hydronium jarosite

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zhihui [Department of Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095 (China); Liang, Jianru [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Zhou, Lixiang, E-mail: lxzhou@njau.edu.cn [Department of Environmental Engineering, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China)

    2013-01-05

    Highlights: Black-Right-Pointing-Pointer Hydronium and ammonium jarosite could catalyze the oxidation of methyl orange in photo-Fenton-like process. Black-Right-Pointing-Pointer The oxidation process is essentially heterogeneous, not homogeneous. Black-Right-Pointing-Pointer Hydronium jarosite has stronger reactivity than ammonium jarosite. - Abstract: Ammonium and hydronium jarosite were prepared by hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectrum, UV-vis spectra and fourier transform infrared spectrum were used to characterize the resulting products. The photodegradation efficiency of the prepared ammonium and hydronium jarosite was studied in a photo-Fenton-like process using methyl orange (MO) as target pollutant. The photocatalytic degradation of MO over synthetic ammonium and hydronium jarosite under various conditions, such as catalysts loading, H{sub 2}O{sub 2} concentration and initial pH, has been investigated. Results show that ammonium and hydronium jarosite have satisfactory photocatalysis effect in degradation of MO azo dye, and that the reactivity of hydronium jarosite toward the mineralization of MO was higher than that of ammonium jarosite. The novel ammonium and hydronium jarosite catalysts would be important for industrial applications due to their high photoactivity, little iron leaching and low cost.

  3. Preparation of Polyaniline/TiO2 Composite Nanotubes for Photodegradation of AZO Dyes

    Institute of Scientific and Technical Information of China (English)

    CHENG Yang; AN Liang; ZHAO Zongshan; WANG Guanghui

    2014-01-01

    Polyaniline (PANI) composite nanotubes (90-130 nm in diameter) containing titanium dioxide (TiO2) nanoparticles (about 10 nm in diameter) were synthesized through a self-assembly process in the presence of â-naphthalenesulfonic acid (â-NSA) as the dopant. It was found that PANI-TiO2 composites and PANI nanotubes both behaved with significant photocatalytic activities towards AZO dyes, during 2 h photocatalytic processes under natural light, the degradation ratio was 94.2%and 97.2%respectively (methyl orange and orange II). The morphology of such products was characterized by SEM. The specific surface area of such composite nanotubes was 14.7 m2/g compared to normal polyaniline which was 0.27 m2/g. IR and X-ray diffraction characterizations showed that the chemical chain of the composite nanotubes was identical to that of the doped PANI. It may provide a new way for photodegradation of organic contaminants by using conjugated polymer with dimensional structure.

  4. Magnetically Recyclable Fe3O4@His@Cu Nanocatalyst for Degradation of Azo Dyes.

    Science.gov (United States)

    Kurtan, U; Amir, Md; Baykal, A; Sözeri, H; Toprak, M S

    2016-03-01

    Fe3O4@His@Cu magnetic recyclable nanocatalyst (MRCs) was synthesized by reflux method using L-histidine as linker. The composition, structure and magnetic property of the product were characterized by X-ray powder diffraction (XRD), Scanning electron microscopy (SEM), Fourier Transform infrared spectroscopy (FT-IR) and vibrating sample magnetometry (VSM). Powder XRD, FT-IR and EDAX results confirmed that the as-synthesized products has Fe3O4 with spinel structure and Cu nanoparticles with moderate crystallinity without any other impurities. The surface of the Fe3O4@His nanocomposite was covered by tiny Cu nanoparticles. We examine the catalytic activity of Fe3O4@His@Cu MRCs for the degradation of two azo dyes, methyl orange (MO) and methylene blue (MB) as well as their mixture. The reusability of the nanocatalyst was good and sustained even after 3 cycles. Therefore this innovated Fe3O4@His@Cu MRCs has a potential to be used for purification of waste water. PMID:27455668

  5. Preconcentration of uranium in seawater with heterocyclic azo dyes supported on silica gel

    International Nuclear Information System (INIS)

    The chelating adsorbents, heterocyclic azo dyes supported on silica gel, were prepared and their adsorption behaviors of metal ions were investigated. The 1-(2-pyridylazo)-2-naphthol(PAN)-SG and 2-(2-thiazolylazo)-p-cresol(TAC)-SG show greater affinity for UO2(II) and ZrO(II), compared with the other metal ions like Cu, Cd, Fe and alkaline earths. Trace uranyl can be quantitatively retained on the column of the gels at neutral pH region and flowrate 3-4 ml/min. The uranyl retained is easily eluted from the column bed with a mixture of acetone and nitric acid (9:1 v/v) and determined by spectrophotometry using Arsenazo-III. Matrix components in seawater do not interfere and the spiked recovery of uranyl in artificial seawater was found to be average 98.6%, with the relative standard deviation of 1.08%. Both gels were applied to the determination of uranium in seawater with satisfactory results. 16 references, 3 figures, 3 tables

  6. Synergistic Decolouration of Azo Dye by Pulsed Streamer Discharge Immobilized TiO2 Photocatalysis

    Institute of Scientific and Technical Information of China (English)

    LI Jie; WANG Huijuan; LI Guofeng; WU Yan; QUAN Xie; LIU Zhigang

    2007-01-01

    Photocatalyst was prepared by immobilizing TiO2 on glass beads using the traditional sol-gel method.Ultraviolet light(UV)produced by pulsed streamer discharge Was then used to induce photocatalytic activity of TiO2 photocatalyst.Decolouration efficiency of the representative azo dye(acid orange 7,AO7)was investigated using the synergistic system of pulsed streamer discharge plasma and TiO2 photocatalysis.The obtained results showed that the decolouration rate of AO7 could be increased by 16.7% under the condition of adding supported TiO2 in the pulsed streamer discharge system,compared to that in the sole pulsed streamer discharge plasma system,due to the synergistic effect of pulsed streamer discharge and TiO2 photocatalysis induced by pulsed streamer discharge.The synergistic system of pulsed streamer discharge and TiO2 photocatalyst Was found to have more reactive radicals for degradation of organic compounds in Water.

  7. Photo-Fenton-like degradation of azo dye methyl orange using synthetic ammonium and hydronium jarosite

    International Nuclear Information System (INIS)

    Highlights: ► Hydronium and ammonium jarosite could catalyze the oxidation of methyl orange in photo-Fenton-like process. ► The oxidation process is essentially heterogeneous, not homogeneous. ► Hydronium jarosite has stronger reactivity than ammonium jarosite. - Abstract: Ammonium and hydronium jarosite were prepared by hydrothermal method with urea as the homogeneous precipitant. X-ray diffraction, field-emission scanning electron microscope, X-ray photoelectron spectrum, UV–vis spectra and fourier transform infrared spectrum were used to characterize the resulting products. The photodegradation efficiency of the prepared ammonium and hydronium jarosite was studied in a photo-Fenton-like process using methyl orange (MO) as target pollutant. The photocatalytic degradation of MO over synthetic ammonium and hydronium jarosite under various conditions, such as catalysts loading, H2O2 concentration and initial pH, has been investigated. Results show that ammonium and hydronium jarosite have satisfactory photocatalysis effect in degradation of MO azo dye, and that the reactivity of hydronium jarosite toward the mineralization of MO was higher than that of ammonium jarosite. The novel ammonium and hydronium jarosite catalysts would be important for industrial applications due to their high photoactivity, little iron leaching and low cost.

  8. Anion recognition ability of a novel azo dye derived from 4-hydroxycoumarin

    Energy Technology Data Exchange (ETDEWEB)

    Chandel, Madhurya; Roy, Sutapa Mondal; Sharma, Darshna [Department of Applied Chemistry, SV National Institute of Technology, Surat, Gujarat (India); Sahoo, Suban K., E-mail: suban_sahoo@rediffmail.com [Department of Applied Chemistry, SV National Institute of Technology, Surat, Gujarat (India); Patel, Amit; Kumari, Premlata [Department of Applied Chemistry, SV National Institute of Technology, Surat, Gujarat (India); Dhale, Ranu S. [School of Chemical Sciences, National Institute of Science Education and Research, Bhubaneswar, Odisha (India); Ashok, Kumar S.K. [School of Advanced Sciences, VIT University, Vellore, Tamil Nadu (India); Nandre, Jitendra P.; Patil, Umesh D. [School of Chemical Sciences, North Maharashtra University, Jalgaon, Maharashtra (India)

    2014-10-15

    The anion recognition ability of a novel azo dye derived from 4-hydroxycuomarin (L) was investigated by experimental (UV–vis, fluorescence and {sup 1}H NMR) and theoretical [(B3LYP/6-31G(d,p)] methods. Among the surveyed anions, the receptor L showed both naked-eye detectable color and spectral changes in the presence of F{sup −}, AcO{sup −} and H{sub 2}PO{sub 4}{sup −} due to the formation of hydrogen bonding complexes followed by deprotonation between these anions and L. - Highlights: • Anion recognition ability of an easy-to-prepare coumarin derivative L was reported. • L showed both naked-eye and spectral responses towards AcO{sup −}, F{sup −} and H{sub 2}PO{sub 4}{sup −}. • Deprotonation mechanism was proposed for the observed spectral responses. • L showed selective ratiometric fluorescence ‘turn-on’ responses towards AcO{sup −} and F{sup −}.

  9. Solid-phase extraction and simultaneous determination of trace amounts of sulphonated and azo sulphonated dyes using microemulsion-modified-zeolite and multivariate calibration.

    Science.gov (United States)

    Al-Degs, Yahya S; El-Sheikh, Amjad H; Al-Ghouti, Mohammad A; Hemmateenejad, Bahram; Walker, Gavin M

    2008-05-30

    A simple and rapid analytical method for the determination of trace levels of five sulphonated and azo sulphonated reactive dyes: Cibacron Reactive Blue 2 (C-Blue, trisulphonated dye), Cibacron Reactive Red 4 (C-Red, tetrasulphonated azo dye), Cibacron Reactive Yellow 2 (C-Yellow, trisulphonated azo dye), Levafix Brilliant Red E-4BA (L-Red, trisulphonated dye), and Levafix Brilliant Blue E-4BA (L-Blue, disulphonated dye) in water is presented. Initially, the dyes were preconcentrated from 250 ml of water samples with solid-phase extraction using natural zeolite sample previously modified with a microemulsion. The modified zeolite exhibited an excellent extraction for the dyes from solution. The parameters that influence quantitative recovery of reactive dyes like amount of extractant, volume of dye solution, pH, ionic strength, and extraction-elution flow rate were varied and optimized. After elution of the adsorbed dyes, the concentration of dyes was determined spectrophotometrically with the aid of principle component regression (PCR) method without separation of dyes. The results obtained from PCR method were comparable to those obtained from HPLC method confirming the effectiveness of the proposed method. With the aid of SPE by M-zeolite, the concentration of dyes could be reproducibly detected over the range 25-200 ppb for C-Yellow and L-Blue and from 50 to 250 ppb for C-Blue, C-Red, and L-Red. The multivariate detection limits of dyes were found to be 15 ppb for C-Yellow and L-Blue and 25 ppb for C-Blue, C-Red, and L-Red dyes. The proposed chemometric method gave recoveries from 85.4 to 115.3% and R.S.D. from 1.0 to 14.5% for determination of the five dyes without any prior separation for solutes. PMID:18585163

  10. Deciphering effects of functional groups and electron density on azo dyes degradation by graphene loaded TiO2

    Science.gov (United States)

    Zhang, Qian; Liang, Xiao; Chen, Bor-Yann; Chang, Chang-Tang

    2015-12-01

    This study tended to decipher the mechanism of photo degradation of azo dyes, which bond was favorable to be broken for application of wastewater decolorization. That is, from chemical structure perspective, the critical substituents to affect electron donor/acceptor for dye degradation would be identified in this research. The model reactive blacks (RB5), reactive blue 171 (RB171) and reactive red 198 (RR198) were degraded by graphene loaded TiO2, indicating how the electron withdrawing and releasing groups affect azo dye degradability. The byproducts and intermediate products were analyzed by ultraviolet-visible spectroscopy (UV-vis), gas chromatography-mass spectrometry (GC-MS) and ion chromatography (IC). Furthermore, the radicals involved in the reaction were found by electron paramagnetic resonance (ESR) to confirm the main oxidized species of hydroxyl radicals rather than the light generated positive holes. The finding revealed that the breakages of the bonds were due to the electron density changes around the bonds. This principle can be applicable not only for RB5 degradation, but also for reactive blue 171 (RB171), reactive red 198 (RR198) and some other textile dyes.

  11. Influence of organic and inorganic compounds on oxidoreductive decolorization of sulfonated azo dye C.I. Reactive Orange 16

    International Nuclear Information System (INIS)

    An isolated bacterial strain is placed in the branch of the Bacillus genus on the basis of 16S rRNA sequence and biochemical characteristics. It decolorized an individual and mixture of dyes, including reactive, disperse and direct. Bacillus sp. ADR showed 88% decolorization of sulfonated azo dye C.I. Reactive Orange 16 (100 mg L-1) with 2.62 mg of dye decolorized g-1 dry cells h-1 as specific decolorization rate along with 50% reduction in COD under static condition. The optimum pH and temperature for the decolorization was 7-8 and 30-40 oC, respectively. It was found to tolerate the sulfonated azo dye concentration up to 1.0 g L-1. Significant induction in the activity of an extracellular phenol oxidase and NADH-DCIP reductase enzymes during decolorization of C.I. Reactive Orange 16 suggest their involvement in the decolorization. The metal salt (CaCl2), stabilizers (3,4-dimethoxy benzyl alcohol and o-tolidine) and electron donors (sodium acetate, sodium formate, sodium succinate, sodium citrate and sodium pyruvate) enhanced the C.I. Reactive Orange 16 decolorization rate of Bacillus sp. ADR. The 6-nitroso naphthol and dihydroperoxy benzene were final products obtained after decolorization of C.I. Reactive Orange 16 as characterized using FTIR and GC-MS.

  12. Simultaneous removal of color, organic compounds and nutrients in azo dye-containing wastewater using up-flow constructed wetland

    International Nuclear Information System (INIS)

    Combination of aerobic and anaerobic processes in constructed wetlands can enhance the treatment performance in textile wastewater. This study assessed the treatment of azo dye Acid Orange 7 (AO7) and nutrients using five laboratory-scale up-flow constructed wetlands (UFCW) with and without supplementary aeration, and with different emergent plants. Supplementary aeration controlled the size of aerobic and anaerobic zones in the UFCW reactors as evidenced by the oxidation-reduction potential (ORP) and dissolved oxygen (DO) profile of the UFCW. The AO7 removal efficiency was above 95% in all UFCW reactors and most of the color was extensively removed in the anaerobic region of the UFCW beds. The intermediates produced through the breakage of azo bond were significantly reduced in the UFCW reactors with supplementary aeration. The results indicated the applicability of the UFCW reactors to the treatment of azo dye-containing wastewater. The removals of T-N and T-P were in the range of 60-67% and 26-37%, respectively, among the UFCW reactors. The COD and NH4-N removals in the aerated reactors were about 86 and 96%, respectively. On the other hand, the COD and NH4-N removals were in the range of 78-82% and 41-48%, respectively, in the non-aerated reactors. The supplementary aeration enhanced the removal efficiencies in organic matter, NH4-N and aromatic amines in the UFCW reactors.

  13. Degradation process analysis of the azo dyes by catalytic wet air oxidation with catalyst CuO/γ-Al2O3.

    Science.gov (United States)

    Hua, Li; Ma, Hongrui; Zhang, Lei

    2013-01-01

    Three azo dyes (Methyl Orange, Direct Brown and Direct Green) were treated by catalytic wet air oxidation (CWAO) with the catalysts CuO/γ-Al(2)O(3) prepared by consecutive impregnation. The relationship of decolorization extent, chemical oxygen demand (COD) removal extent and total organic carbon (TOC) in dye solution were investigated. The results indicated that the CuO/γ-Al(2)O(3) catalyst had excellent catalytic activity in treating azo dyes. Almost 99% of color and 70% of TOC were removed in 2h. The high removal extent of color and TOC indicated that the CWAO obtained perfect decomposition for pollutants. The degradation pathway of azo dyes was analyzed by UV-Vis, FTIR and MS. According to the examined results, the hydroxyl ((·)OH) radicals induced strong oxidizing effects in the target solution and destroyed the chromophoric groups of azo-benzene conjugated of the molecular structure. Considering characteristics of the dye structure, the azo bond (-N=N-) would first be attacked by the hydroxyl radical and other free radicals. With the continuous oxidization and the long reaction time at high temperature, these intermediates could be oxidized to the final oxidation products, such as water and carbon dioxide. PMID:22795071

  14. Design, synthesis and characterization of the electrochemical, nonlinear optical properties and theoretical studies of novel thienylpyrrole azo dyes bearing benzothiazole acceptor groups

    OpenAIRE

    Raposo, M. Manuela M.; Castro, M. Cidália R.; Fonseca, A. Maurício C.; Schellenberg, Peter Michael; Belsley, M.

    2011-01-01

    Two series of related donor-acceptor conjugated heterocyclic azo dyes based on the thienylpyrrole system, functionalized with benzothiazol-2-yl (5-6) or benzothiazol-6-yl acceptor groups (7) through an N=N bridge, have been synthesized by azo coupling using 1-alkyl(aryl)thienylpyrroles (1) and benzothiazolyl diazonium salts (2-4) as coupling components. Their optical (linear and first hyperpolarizability), electrochemical and thermal properties have been examined. Optimized ground-state molec...

  15. Isolation and characterization of a Klebsiella oxytoca strain for simultaneous azo-dye anaerobic reduction and bio-hydrogen production.

    Science.gov (United States)

    Yu, Lei; Li, Wen-Wei; Lam, Michael Hon-Wah; Yu, Han-Qing; Wu, Chao

    2012-07-01

    A facultative anaerobic bacteria strain GS-4-08, isolated from an anaerobic sequence batch reactor for synthetic dye wastewater treatment, was investigated for azo-dye decolorization. This bacterium was identified as a member of Klebsiella oxytoca based on Gram staining, morphology characterization and 16S rRNA gene analysis. It exhibited a good capacity of simultaneous decolorization and hydrogen production in the presence of electron donor. The hydrogen production was less affected even at a high Methyl Orange (MO) concentration of 0.5 mM, indicating a superior tolerability of this strain to MO. This efficient bio-hydrogen production from electron donor can not only avoid bacterial inhibition due to accumulation of volatile fatty acids during MO decolorization, but also can recover considerable energy from dye wastewater. PMID:22086069

  16. Spectroscopic and theoretical study of the "azo"-dye E124 in condensate phase: evidence of a dominant hydrazo form.

    Science.gov (United States)

    Almeida, Mariana R; Stephani, Rodrigo; Dos Santos, Hélio F; de Oliveira, Luiz Fernando C

    2010-01-14

    Spectroscopic techniques, including Raman, IR, UV/vis, and NMR were used to characterize the samples of the azo dye Ponceau 4R (also known as E124, New Coccine; Cochineal Red; C.I. no. 16255; Food Red No. 102), which is 1,3-naphthalenedisulfonic acid, 7-hydroxy-8-[(4-sulfo-1-naphthalenyl) azo] trisodium salt in aqueous solution and solid state. In addition, first principle calculations were carried out for the azo (OH) and hydrazo (NH) tautomers in order to assist in the assignment of the experimental data. The two intense bands observed in the UV/vis spectrum, centered at 332 and 507 nm, can be compared to the calculated values at 296 and 474 nm for azo and 315 and 500 nm for hydrazo isomer, with the latter in closer agreement to the experiment. The Raman spectrum is quite sensitive to tautomeric equilibrium; in solid state and aqueous solution, three bands were observed around 1574, 1515, and 1364 cm(-1), assigned to mixed modes including deltaNH + betaCH + nuCC, deltaNH + nuC horizontal lineO + nuC horizontal lineN + betaCH and nuCC vibrations, respectively. These assignments are predicted only for the NH species centered at 1606, 1554, and 1375 cm(-1). The calculated Raman spectrum for the azo (OH) tautomer showed two strong bands at 1468 (nuN = N + deltaOH) and 1324 cm(-1) (nuCC + nuC-N), which were not obtained experimentally. The (13)C NMR spectrum showed a very characteristic peak at 192 ppm assigned to the carbon bound to oxygen in the naphthol ring; the predicted values were 165 ppm for OH and 187 for NH isomer, supporting once again the predominance of NH species in solution. Therefore, all of the experimental and theoretical results strongly suggest the food dye Ponceau 4R or E124 has a major contribution of the hydrazo structure instead of the azo form as the most abundant in condensate phase. PMID:19852449

  17. Surface-enhanced Raman scattering (SERS) spectra of three kinds of azo-dye molecules on silver nanoparticles prepared by electrolysis

    International Nuclear Information System (INIS)

    Silver nanoparticles were prepared by an electrolysis method. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to detect the morphology of these particles. Based on this high active surface enhanced Raman scattering (SERS) substrate, three kinds of azo-dye molecules (Methyl Yellow, Methyl Red and Sudan Red 1) were carefully studied. Using the Gaussian’98 software, we gained the calculation result of these three kinds of azo-dye molecules, and found that the calculation results had good concordance with the experimental one. The detection limit of azo-dye molecules on the silver nanoparticles can go down to 10-5 mol/l, which indicated that these particles were an active SERS substrate.

  18. Properties of the metallochromic dyes Arsenazo III, Antipyrylazo III and Azo1 in frog skeletal muscle fibres at rest.

    Science.gov (United States)

    Baylor, S M; Hollingworth, S; Hui, C S; Quinta-Ferreira, M E

    1986-08-01

    Intact single twitch fibres from frog muscle were isolated and mounted in a normal Ringer solution (16 degrees C) on an optical bench apparatus for measuring fibre absorbance as a function of the wave-length and polarization of the incident light. Fibre absorbance was measured in resting fibres both in the absence and in the presence of one of three metallochromic dyes: Arsenazo III, Antipyrylazo III and Azo1. In the absence of dye, the fibre intrinsic absorbance, Ai(lambda), measured as a function of wave-length, lambda, was well described by the equation: Ai(lambda) = Ai(lambda long) (lambda long/lambda)X, where lambda long is a reference wave-length selected to lie beyond the absorbance band of the dyes and X is the exponential index. For wave-lengths between 480 and 810 nm, the average value of X was 1.1 for 0 deg polarized light (electric vector parallel to the fibre axis) and 1.3 for 90 deg polarized light (electric vector perpendicular to the fibre axis). The intrinsic absorbance at 0 deg, Ai,0(lambda), was somewhat larger than the intrinsic absorbance at 90 deg, Ai,90(lambda); for example, on average (n = 6), Ai,0 (810 nm) was 0.22, whereas Ai,90 (810 nm) was 0.016. Following dye injection, dye-related absorbance was estimated from the measured total fibre absorbance by subtracting the component attributable to the intrinsic absorbance; additionally, for comparison with in vitro calibrations as a function of wave-length, myoplasmic dye absorbance was corrected for the steady change in dye-concentration with time that was attributable to dye diffusion. In fibres injected with either Arsenazo III or Antipyrylazo III, the dye-related absorbance measured with 0 deg light, A0(lambda), was found to be significantly greater than that measured with 90 deg light, A90(lambda), indicating the presence of a resting 'dichroic' signal, A0(lambda)-A90(lambda), attributable to bound and oriented dye molecules. On average, the lower limit estimated for the percentage of

  19. Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis.

    Science.gov (United States)

    Wang, Hong-Cheng; Cheng, Hao-Yi; Wang, Shu-Sen; Cui, Dan; Han, Jing-Long; Hu, Ya-Ping; Su, Shi-Gang; Wang, Ai-Jie

    2016-01-01

    In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3%±2.5%, 86.2%±3.8% and 93.5%±1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1%±4.7%, 75.4%±5.0% and 82.1%±2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2%±3.7% and 28.30±1.48 mA, respectively. They were significantly increased to 62.1%±2.0% and 34.55±0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater. PMID:26899658

  20. Solar Photocatalytic Degradation of Azo Dye in Aqueous TiO2 Suspension Assisted by Fresnel Lens

    OpenAIRE

    Wen-Shiuh Kuo; Wen-Yu Chen

    2012-01-01

    Solar TiO2 photocatalytic process assisted by a Fresnel lens was investigated for treating an azo dye wastewater of Acid Orange 10 (AO10). Response surface methodology (RSM) was employed to assess the effect of critical process parameters (including initial pH of wastewater, concentration of TiO2, and reaction time) on treatment performance in terms of COD and TOC degradation efficiency. Optimized reaction conditions based on the analysis of RSM were established under an initial pH of 6.0, a ...

  1. Ant colony optimization as a descriptor selection in QSPR modeling for prediction of λmax of azo dyes

    Institute of Scientific and Technical Information of China (English)

    Morteza Atabati; Farzaneh Khandani

    2012-01-01

    A quantitative structure-property relationship (QSPR) study was suggested for the prediction of λmax of azo dyes.After optimization of 3D geometry of structures,different descriptors were calculated by the HyperChem and Dragon softwares.A major problem of QSPR is the high dimensionality of the descriptor space; therefore,descriptor selection is the most important step for these studies.In this paper,an ant colony optimization (ACO) algorithm was proposed to select the best descriptors.

  2. Laccase-catalyzed decolorization of the synthetic azo-dye diamond black PV 200 and of some structurally related derivatives

    OpenAIRE

    A. Kandelbauer; Erlacher, Angelika; Paulo, Artur Cavaco

    2004-01-01

    The kinetics of laccase-catalyzed transformation of the azo-dye Diamond Black PV 200 (CI Mordant Black 9) and various related synthesized derivatives were analyzed for dependence on pH and substrate structure. The reaction mixture of Diamond Black PV 200 was analyzed by HPLC/MS_/MS and it was shown that upon laccase oxidation, reactive chinoid fragments of lower molecular weight were formed. These may further oligomerize as indicated by the appearance of a number of compounds with incre...

  3. Effect of addition of heavy metal ion on decolouration and degradation of azo dye in aqueous solution by gamma irradiation combined with ozone

    International Nuclear Information System (INIS)

    In decomposition of azo dyes solution by simultaneous application of gamma-ray and ozone treatment, the effect of addition of heavy metal ion upon decolouration and decomposition was studied. Cupric ion was used as a heavy metal ion. For the aqueous solution with and without addition of cupric ion, the degree of decolouration of 552 nm, the changes of pH, the reduction of TOC and BOD were measured as function of dose under condition of fixed concentration of ozone. It appeared that the addition of cupric ion played a positive role in decomposition of azo dye solution, but played a negative role in decolouration

  4. Decolorization and detoxification of Synozol red HF-6BN azo dye, by Aspergillus niger and Nigrospora sp

    Directory of Open Access Journals (Sweden)

    Sidra Ilyas

    2013-01-01

    Full Text Available In the present investigation the fungi, Aspergillus niger and Nigrospora sp. were employed for decolorization of Synazol red HF-6BN. Decolorization study showed that Aspergillus niger and Nigrospora sp. were able to decolorize 88% and 96% Synazol red 6BN, respectively, in 24 days. It was also studied that 86% and 90% Synazol red containing of dye effluent was decolorized by Aspergillus niger and Nigrospora sp. after 28 days of incubation at room temperature. A fungal-based protein with relative molecular mass of 70 kDa was partially purified and examined for enzymatic characteristics. The enzyme exhibited highest activity at temperature ranging from 40-50[degree sign]C and at pH=6.0. The enzyme activity was enhanced in the presence of metal cations. High performance liquid chromatography analysis confirmed that these fungal strains are capable to degrade Synazol red dye into metabolites. No zones of inhibition on agar plates and growth of Vigna radiata in the presence of dye extracted sample, indicated that the fungal degraded dye metabolites are nontoxic to beneficial micro-flora and plant growth. Aspergillus niger and Nigrospora sp. have promising potential in color removal from textile wastewater-containing azo dyes.

  5. Cyclodextrin-induced host–guest effects of classically prepared poly(NIPAM bearing azo-dye end groups

    Directory of Open Access Journals (Sweden)

    Gero Maatz

    2012-11-01

    Full Text Available A thermo-, pH- and cyclodextrin- (CD responsive poly(N-isopropylacrylamide (PNIPAM, with a N,N-dimethylaminoazobenzene end group was synthesized. Using 3-mercaptopropionic acid as a chain transfer agent, PNIPAM with a well-defined COOH end group was obtained. The acid end group was transferred to the corresponding acid chloride and then functionalized with N,N-dimethyl[4-(4’-aminophenylazophenyl]amine. This dye-end-group-labeled polymer showed acidochromic effects, depending on the pH and the presence of randomly methylated β-cyclodextrin (RAMEB-CD. Also higher cloud-point values for the lower critical solution temperature (LCST in the presence of RAMEB-CD were observed. Additionally, this azo-dye-end-group-labeled polymer was complexed with hyperbranched polyglycerol (HPG decorated with β-CD to generate hedgehog-like superstructures.

  6. Remediation of textile azo dye acid red 114 by hairy roots of Ipomoea carnea Jacq. and assessment of degraded dye toxicity with human keratinocyte cell line.

    Science.gov (United States)

    Jha, Pamela; Jobby, Renitta; Desai, N S

    2016-07-01

    Bioremediation has proven to be the most desirable and cost effective method to counter textile dye pollution. Hairy roots (HRs) of Ipomoea carnea J. were tested for decolourization of 25 textile azo dyes, out of which >90% decolourization was observed in 15 dyes. A diazo dye, Acid Red 114 was decolourized to >98% and hence, was chosen as the model dye. A significant increase in the activities of oxidoreductive enzymes was observed during decolourization of AR114. The phytodegradation of AR114 was confirmed by HPLC, UV-vis and FTIR spectroscopy. The possible metabolites were identified by GCMS as 4- aminobenzene sulfonic acid 2-methylaniline and 4- aminophenyl 4-ethyl benzene sulfonate and a probable pathway for the biodegradation of AR114 has been proposed. The nontoxic nature of the metabolites and toxicity of AR114 was confirmed by cytotoxicity tests on human keratinocyte cell line (HaCaT). When HaCaT cells were treated separately with 150μgmL(-1) of AR114 and metabolites, MTT assay showed 50% and ≈100% viability respectively. Furthermore, flow cytometry data showed that, as compared to control, the cells in G2-M and death phase increased by 2.4 and 3.6 folds respectively on treatment with AR114 but remained unaltered in cells treated with metabolites. PMID:26971029

  7. Statement on Allura Red AC and other sulphonated mono azo dyes authorised as food and feed additives

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS

    2013-06-01

    Full Text Available The ANS Panel has been asked by EFSA to assess the new scientific information that has become available since the adoption of the opinion on the re-evaluation of the food colouring agent Allura Red AC in 2009, in particular the positive findings from an in vivo comet assay in mice. The findings from this study have been interpreted in conjunction with all the available relevant data from genotoxicity testing, metabolism and carcinogenicity, and in consideration of possible species differences between mouse and rat. These new data have been considered in the context of the overall relevant data available not only for Allura Red AC but also for a number of other structurally related sulphonated mono azo dyes authorised as food additives, namely: Amaranth, Ponceau 4R, Sunset Yellow FCF, Tartrazine and Azorubine/Carmoisine. The Panel concluded that the new data by themselves were insufficient at this time to change the conclusions of the 2009 opinion on the safety of Allura Red AC and that there is currently no reason to revise the ADI. The read-across exercise has highlighted a shared pattern of effects for this class of substances that would warrant further investigation The Panel therefore recommended a repetition of the in vivo comet assay in mice, to be performed in compliance with the most recent and internationally validated experimental protocol, using whole cells and examining a wide range of tissues. These recommendations apply to all the sulphonated mono azo dyes included in this review.

  8. Degradation of a model azo dye in submerged anaerobic membrane bioreactor (SAMBR) operated with powdered activated carbon (PAC).

    Science.gov (United States)

    Baêta, B E L; Luna, H J; Sanson, A L; Silva, S Q; Aquino, S F

    2013-10-15

    This work investigated the anaerobic degradation of the model azo dye Remazol Yellow Gold RNL in an upflow anaerobic sludge blanket reactor (UASB) and two submerged anaerobic membrane (SAMBR) bioreactors, one of which (SAMBR-1) was operated with powdered activated carbon (PAC) in its interior. The reactors were operated at 35 °C with a hydraulic retention time of 24 h in three operational phases, aimed to assess the effect of external sources of carbon (glucose) or redox mediator (yeast extract) on the removal or color and organic matter. The results showed that removal efficiencies of COD (73-94%) and color (90-94%) were higher for SAMBR-1 when compared to SAMBR-2 (operated without PAC) and UASB reactors. In addition, the presence of PAC in SAMBR-1 increased reactor stability, thereby leading to a lower accumulation of volatile fatty acids (VFA). The microfiltration membrane was responsible for an additional removal of ~50% of soluble residual COD in the form of VFA, thus improving permeate quality. On its turn, PAC exhibited the ability to adsorb byproducts (aromatic amines) of azo dye degradation as well as to act as source of immobilized redox mediator (quinone groups on its surface), thereby enhancing color removal. PMID:23810998

  9. Synthesis of Mg–Zn–Ca metallic glasses by gas-atomization and their excellent capability in degrading azo dyes

    International Nuclear Information System (INIS)

    Highlights: • Mg–Zn–Ca metallic glass powders were synthesized by gas-atomization. • The phase structure of powders was affected by the composition and the size. • Degradation capacity of powders is determined by phase constituents and Mg content. • Nano-whiskers are distributed loosely on the reacted surface of the glassy powder. -- Abstract: Mg–Zn–Ca powders of Mg63+xZn32−xCa5 (x = 0, 3, 7 and 10) with the diameter from 2 μm to 180 μm were synthesized by gas-atomization. The relationship among powder morphology, the composition, glass forming ability, thermal stability, corrosion resistance and the capacity in degrading azo dyes for these powders was investigated. It is shown that fully glass powders with the particle diameter 70Zn25Ca5 glassy powder, which is considered as the mechanism of high degrading capacity for these Mg–Zn–Ca glassy alloys. This work will contribute to the development of massive production of high quality metallic glass powders with excellent capability in degrading azo dyes

  10. Evaluation of the adsorbent properties of a zeolite rock modified for the removal of the azo dyes as water pollutants

    International Nuclear Information System (INIS)

    At the moment some investigations which make reference to the removal of dyes for diverse adsorbent materials; as well as the factors that influence in the sorption process, considering the type so much of dye as those characteristics of the adsorbent material. In this work were investigated those adsorbent properties of a zeolite rock coming from San Luis Potosi State for the removal of azo dyes, using as peculiar cases the Red 40 (Red Allura) and the Yellow 5 (Tartrazine); for it were determined kinetic parameters and the sorption isotherms, as well as the sorption mechanisms involved in each case, between the dyes and the zeolite rock. In this work also it was considered the characterization before and after to removal of color from the water, through advanced analytical techniques such as the scanning electron microscopy of high vacuum (SEM), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part of the work fundamentally consisted, in the conditioning with a NaCl solution and later on the modification with HDTMA-Br of the natural zeolite rock, for then to put it in contact with solutions of the dyes R-40 and A-5, varying so much the contact times as the concentrations; the quantification of sodium in the liquid phase after the modification of the zeolite rock to determine the capacity of external cation exchange (CICE) it was carried out by means of the atomic absorption spectroscopy technique (EAA), and the quantification of the surfactant and the dyes in the liquid phase, it was carried out by means of the UV-vis spectrophotometry technique. It was found that the kinetic model that better it describes the process of sorption of R-40 and A-5 for the modified zeolite rock with HDTMA-Br, leaving of monocomponent and bi component solutions, it is the pseudo- second order. Inside of the obtained results for the sorption isotherms, as much the dye R-40 as the dye A-5 its presented a better adjustment to the Langmuir model. In what refers

  11. Heterogenous Photocatalysis Treatement of Azo Dye Methyl Orange by Nano Composite Tio2/Diatomite

    Directory of Open Access Journals (Sweden)

    Rachida Cherrak

    2015-09-01

    Full Text Available The objective of this work is to study the removal of an azo dye methyl orange (MeO by dioxide titanium supported on the surface of diatomite, as a new nano-composite by an advanced oxidation method as heterogeneous Photocatalysis. The titanium oxide (Degussa-25 was immobilized on the powder of diatomaceous earth with a very simple method and low expensive. Diatomite used in this study has porosity more 72%; was thermal activated at temperatures of 800 ° c and 900 ° c and 1000 ° C for 2 h and chemically by sulfuric acid at reflux. Photocatalytic degradation of methyl orange use, was studied in the presence of the materials prepared in solution aqueous with different compositions, M1 (1 g diatomite + 0.5 g TiO2 and M2 (5 g diatomite + 0.5 g TiO2. The photocatalytic activity of the prepared catalysts was tested in a single reactor followed by pH analyzes conductivity and the absorbance. The prepared materials exhibit a very porous morphology, which has been confirmed by several methods DRX, SEM and IR. The results of the photocatalytic treatment of water synthetically polluted with MeO at initial concentration 10 ppm showed a good performance for four nano composite prepared: M1TA is composed by material M1 with diatomite treated by sulfuric acid, and M1TT is composed by material M1 with diatomite calcined at 1000 ° C, and M2TA is M2 material with diatomite treated by sulfuric acid, and M2TT is M2 material with diatomite calcined at 1000 ° c. Maximum efficiency of removing MeO that reaches 84% and 72% for M2TA, M1TT According to the kinetic study reveals that the phenomenon is mixed resulting in a rapid response that is established after 30 minutes, the reaction kinetics of the methyl orange photodegradation following the model of the first order.

  12. The azo dye Disperse Orange 1 induces DNA damage and cytotoxic effects but does not cause ecotoxic effects in Daphnia similis and Vibrio fischeri.

    Science.gov (United States)

    Ferraz, Elisa R A; Grando, Marcella Daruge; Oliveira, Danielle P

    2011-08-30

    Azo dyes constitute the largest group of colorants used in industry and can pass through municipal waste water plants nearly unchanged due to their resistance to aerobic treatment, which potentially exposes humans and local biota to adverse effects. Unfortunately, little is known about their environmental fate. Under anaerobic conditions, some azo dyes are cleaved by microorganisms forming potentially carcinogenic aromatic amines. In the present study, the azo dye Disperse Orange 1, widely used in textile dyeing, was tested using the comet, Salmonella/microsome mutagenicity, cell viability, Daphnia similis and Microtox(®) assays. The human hepatoma cell line (HepG2) was used in the comet assay and for cell viability. In the mutagenicity assay, Salmonella typhimurium strains with different levels of nitroreductase and o-acetyltransferase were used. The dye showed genotoxic effects with respect to HepG2 cells at concentrations of 0.2, 0.4, 1.0, 2.0 and 4.0μg/mL. In the mutagenicity assay, greater responses were obtained with the strains TA98 and YG1041, suggesting that this compound mainly induces frameshift mutations. Moreover, the mutagenicity was greatly enhanced with the strains overproducing nitroreductase and o-acetyltransferase, showing the importance of these enzymes in the mutagenicity of this dye. In addition, the compound induced apoptosis after 72h in contact with the HepG2 cells. No toxic effects were observed for either D. similis or Vibrio fischeri. PMID:21683525

  13. Batch and fixed-bed adsorption of tartrazine azo-dye onto activated carbon prepared from apricot stones

    Science.gov (United States)

    Albroomi, H. I.; Elsayed, M. A.; Baraka, A.; Abdelmaged, M. A.

    2016-02-01

    This work describes the potential of utilizing prepared activated carbon from apricot stones as an efficient adsorbent material for tartrazine (TZ) azo-dye removal in a batch and dynamic adsorption system. The results revealed that activated carbons with well-developed surface area (774 m2/g) and pore volume (1.26 cm3/g) can be manufactured from apricot stones by H3PO4 activation. In batch experiments, effects of the parameters such as initial dye concentration and temperature on the removal of the dye were studied. Equilibrium was achieved in 120 min. Adsorption capacity was found to be dependent on the initial concentration of dye solution, and maximum adsorption was found to be 76 mg/g at 100 mg/L of TZ. The adsorption capacity at equilibrium (q e) increased from 22.6 to 76 mg/g with an increase in the initial dye concentrations from 25 to 100 mg/L. The thermodynamic parameters such as change in free energy (ΔG 0), enthalpy (ΔH 0) and entropy (ΔS 0) were determined and the positive value of (ΔH) 78.1 (K J mol-1) revealed that adsorption efficiency increased with an increase in the process temperature. In fixed-bed column experiments, the effect of selected operating parameters such as bed depth, flow rate and initial dye concentration on the adsorption capacity was evaluated. Increase in bed height of adsorption columns leads to an extension of breakthrough point as well as the exhaustion time of adsorbent. However, the maximum adsorption capacities decrease with increases of flow rate. The breakthrough data fitted well to bed depth service time and Thomas models with high coefficient of determination, R 2 ≥ 94.

  14. Interaction between pH and conductivity in the indirect electro-oxidation of azo dyes

    OpenAIRE

    Gutiérrez Bouzán, María Carmen; Pepió Viñals, Montserrat

    2014-01-01

    The indirect electro-oxidation of dyes results in a rapid break of the dye molecules. The influence of the dye chromophore in this process has already been demonstrated. In this work, an electrochemical treatment in a batch cell with Ti/Pt anode is applied to degrade two reactive dyes (Color Index Reactive Oranges 4 and 13) in the presence of chloride ions, usually used as dyeing electrolyte. For the two dyes, kinetic constants were modeled. A clear influence of the reactive group in the resp...

  15. Low-temperature-fabricated ZnO, AZO, and SnO2 nanoparticle-based dye-sensitized solar cells

    Science.gov (United States)

    Kim, Hong Hee; Park, Cheolmin; Choi, WonKook; Cho, Sungjae; Moon, ByungJoon; Son, Dong Ick

    2014-11-01

    The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO2 based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 °C) dye-sensitized ZnO, AZO, and SnO2 nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO2 nanoparticle layer which forms a nano porous ZnO, AZO, and SnO2 network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density ( J sc ), the open circuit potential ( V oc ), the fill factor (FF), and power conversion efficiency ( η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm2, 0.61 V, 0.46, and 1.43%, respectively.

  16. Kinetic study of the indirect electro-oxidation of azo reactive dyes

    OpenAIRE

    López Grimau, Víctor; Pepió Viñals, Montserrat; Gutiérrez Bouzán, María Carmen

    2015-01-01

    In this work, an electrochemical treatment in a batch cell with Ti/Pt anode was applied to degrade two reactive dyes (Color Index Reactive Orange 4 and 13) in the presence of chloride ions, usually used as dyeing electrolyte. For the two dyes, the kinetic of degradation was studied and also kinetic constants were modelled. The influence of several factors such as pH, conductivity, dye concentration and reactive group structure were evaluated. The adjustment of the established mode...

  17. Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor

    OpenAIRE

    Harshad Lade; Sanjay Govindwar; Diby Paul

    2015-01-01

    A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L−1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent...

  18. Low-Cost Biodegradation and Detoxification of Textile Azo Dye C.I. Reactive Blue 172 by Providencia rettgeri Strain HSL1

    OpenAIRE

    Harshad Lade; Sanjay Govindwar; Diby Paul

    2015-01-01

    Present study focuses on exploitation of agricultural waste wheat bran (WB) as growth medium for degradation of textile azo dye C.I. Reactive Blue 172 (RB 172) using a single bacterium P. rettgeri strain HSL1 (GenBank accession number JX853768.1). The bacterium was found to completely decolorize 50 mg L−1 of dye RB 172 within 20 h at 30 ± 0.2°C under microaerophilic incubation conditions. Additionally, significant reduction in COD (85%) and TOC (52%) contents of dye decolorized medium was obs...

  19. Enhanced photoinduced nematic reorientation in mixture with azo-dye-substituted polymer

    CERN Document Server

    Parfenov, A

    2000-01-01

    The optically induced reorientation of nematic liquid crystal doped withazo-dye substituted polymer is investigated measuring photoinducedbirefringence. These measurement reveal the value (Dn~0.1) of inducedbirefringence of liquid crystal with dye polymer which significantly exceedsthe value of birefringence previously obtained in nematic mixture with the lowmolecular weight dye. More than one order of enhancement is connected withlower diffusivity of polymer.

  20. EVALUATION OF AN AZO AND TWO ANTHRAQUINONE DYES FOR ALLERGIC POTENTIAL

    Science.gov (United States)

    Two dye mixtures and the individual component dyes were evaluated for the potential to Induce contact or pulmonary hypersensitivity. hese dye mixtures were suspect because of anecdotal reports of both pulmonary and contact hypersensitivity in assembly workers, and because the com...

  1. ANALYSIS OF ANIONIC METALLIZED AZO AND FORMAZAN DYES BY CAPILLARY ELECTROPHORESIS/MASS SPECTROMETRY

    Science.gov (United States)

    Capillary electrophoresis-mass spectrometry was applied to the separation of several anionic dyes containing copper(II), chromium(III), or cobalt(III) as part of the dye molecule. The dyes were separated using a 110 cmX50 mu m uncoated fused-silica capillary and a 5 mM ammonium a...

  2. Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.

    Science.gov (United States)

    Shen, Nan; Yuan, Shi-Jie; Wu, Chao; Cheng, Yuan-Yuan; Song, Xiang-Ning; Li, Wen-Wei; Tong, Zhong-Hua; Yu, Han-Qing

    2014-05-01

    In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source. PMID:24648142

  3. Enhancement of modulation depth of an all-optical switch using an azo dye-ethyl red film

    International Nuclear Information System (INIS)

    The polymethyl methacrylate (PMMA) film doped with an azo dye ethyl-red (ER) film is employed to demonstrate the properties of an all-optical switch by its photoinduced dichroism and birefringence. We show how to enhance remarkably the modulation depth of all-optical switches almost to 100% by using two linear polarization beams: one beam is inclined at 45° with respect to the probing beam and serves as a pumping beam, and the other beam is perpendicular to the probing beam and used as an erasing beam. Furthermore, a maximum-to-minimum output intensity ratio of 2000:1 is achieved in experiment, which is very useful and important for optical storages and image displays. (classical areas of phenomenology)

  4. Post-treatment of anaerobically degraded azo dye Acid Red 18 using aerobic moving bed biofilm process: Enhanced removal of aromatic amines

    International Nuclear Information System (INIS)

    Highlights: → Biofilm process was applied as post-treatment of anaerobically degraded an azo dye. → More than 65% of the dye total metabolites was completely mineralized. → Based on HPLC analysis, more than 80% of 1-naphthylamine-4-sulfonate was removed. → Inhibition of biofilm growth was increased with increasing the initial dye concentration. → Considerable porous morphology was observed in the SEM photographs of the biofilm. - Abstract: The application of aerobic moving bed biofilm process as post-treatment of anaerobically degraded azo dye Acid Red 18 was investigated in this study. The main objective of this work was to enhance removal of anaerobically formed the dye aromatic metabolites. Three separate sequential treatment systems were operated with different initial dye concentrations of 100, 500 and 1000 mg/L. Each treatment system consisted of an anaerobic sequencing batch reactor (An-SBR) followed by an aerobic moving bed sequencing batch biofilm reactor (MB-SBBR). Up to 98% of the dye decolorization and more than 80% of the COD removal occurred anaerobically. The obtained results suggested no significant difference in COD removal as well as the dye decolorization efficiency using three An-SBRs receiving different initial dye concentrations. Monitoring the dye metabolites through HPLC suggested that more than 80% of anaerobically formed 1-naphthylamine-4-sulfonate was completely removed in the aerobic biofilm reactors. Based on COD analysis results, at least 65-72% of the dye total metabolites were mineralized during the applied treatment systems. According to the measured biofilm mass and also based on respiration-inhibition test results, increasing the initial dye concentration inhibited the growth and final mass of the attached-growth biofilm in MB-SBBRs.

  5. Spectrophotometric determination of sildenafil citrate in pure form and in pharmaceutical formulation using some chromotropic acid azo dyes

    Science.gov (United States)

    Issa, Y. M.; El-Hawary, W. F.; Youssef, A. F. A.; Senosy, A. R.

    2010-04-01

    Two simple and highly sensitive spectrophotometric methods were developed for the quantitative determination of the drug sildenafil citrate (SC), Viagra, in pure form and in pharmaceutical formulations, through ion-associate formation reactions (method A) with mono-chromotropic acid azo dyes, chromotrope 2B (I) and chromotrope 2R (II) and ion-pair reactions (method B) with bi-chromotropic acid azo dyes, 3-phenylazo-6-o-carboxyphenylazo-chromotropic acid (III), bis-3,6-(o-hydroxyphenylazo)-chromotropic acid (IV), bis-3,6-(p-N,N-dimethylphenylazo)-chromotropic acid (V) and 3-phenylazo-6-o-hydroxyphenylazo-chromotorpic acid (VI). The reaction products, extractable in methylene chloride, were quantitatively measured at 540, 520, 540, 570, 600 and 575 nm using reagents, I-VI, respectively. The reaction conditions were studied and optimized. Beer's plots were linear in the concentration ranges 3.3-87.0, 3.3-96.0, 5.0-115.0, 2.5-125.0, 8.3-166.7 and 0.8-15.0 μg mL -1 with corresponding molar absorptivities 1.02 × 10 4, 8.34 × 10 3, 6.86 × 10 3, 5.42 × 10 3, 3.35 × 10 3 and 2.32 × 10 4 L mol -1 cm -1 using reagents I-VI, respectively. The limits of detection and Sandell's sensitivities were calculated. The methods were successfully applied to the analysis of commercial tablets (Vigoran) and the recovery study reveals that there is no interference from the common excipients that are present in tablets. Statistical comparison of the results was performed with regard to accuracy and precision using Student's t- and F-tests at 95% confidence level. There is no significant difference between the reported and proposed methods with regard to accuracy and precision.

  6. The use HPTLC and Direct Analysis in Real Time-Of-Flight Mass Spectrometry DART-TOF-MS for rapid analysis of degradation by oxidation and sonication of an azo dye

    OpenAIRE

    Djelal, Hayet; Cornée, Carole; Tardivel, Ronan; Lavastre, Olivier; Amrane, Abdelatif

    2013-01-01

    Advanced oxidation processes are efficient for the removal of recalcitrant compounds, like azo-dyes. However, the intermediates produced during their degradation can be more toxic than the parent compounds. Improving the knowledge concerning the degradation pathways may be therefore helpful to optimize the process. In this aim, HPTLC and Direct Analysis in Real Time-Of-Flight Mass Spectrometry DART-TOF-MS were considered and applied to analyze the sono-oxidation of an azo dye, methyl red sodi...

  7. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

    Science.gov (United States)

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-01-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment. PMID:27121278

  8. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system.

    Science.gov (United States)

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-01-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m(3)·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolorization (16.23 ± 1.86% for R1 versus 22.24 ± 2.14% for R2) implied that although azo dye was mainly removed in sludge zone, BES further improved the effluent quality, especially for R1 where electrodes were installed in liquid phase. The microbial communities in the electrode biofilms (dominant by Enterobacter) and sludge (dominant by Enterococcus) were well distinguished in R1, but they were similar in R2. These results suggest that electrodes installed in liquid phase in the anaerobic hybrid system are more efficient than that in sludge phase for azo dye removal, which give great inspirations for the application of AD-BES hybrid process for various refractory wastewaters treatment. PMID:27121278

  9. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Dan; Guo, Yu-Qi; Cheng, Hao-Yi; Liang, Bin; Kong, Fan-Ying [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China); Lee, Hyung-Sool [Department of Civil and Environmental Engineering, University of Waterloo, 200 University Avenue West Waterloo, Ontario, Canada N2L 3G1 (Canada); Wang, Ai-Jie, E-mail: waj0578@hit.edu.cn [State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, No. 202 Haihe Road, Harbin 150090 (China)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. Black-Right-Pointing-Pointer Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). Black-Right-Pointing-Pointer PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. Black-Right-Pointing-Pointer The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 {+-} 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m{sup -3} d{sup -1}) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m{sup -3} d{sup -1} (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

  10. Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor

    International Nuclear Information System (INIS)

    Highlights: ► A membrane-free up-flow biocatalyzed electrolysis reactor coupled with an aerobic bio-contact oxidation reactor was developed. ► Alizarin Yellow R as the mode of azo dyes was efficiently converted to p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA). ► PPD and 5-ASA were further oxidized in a bio-contact oxidation reactor. ► The mechanism of UBER for azo dye removal was discussed. - Abstract: Azo dyes that consist of a large quantity of dye wastewater are toxic and persistent to biodegradation, while they should be removed before being discharged to water body. In this study, Alizarin Yellow R (AYR) as a model azo dye was decolorized in a combined bio-system of membrane-free, continuous up-flow bio-catalyzed electrolysis reactor (UBER) and subsequent aerobic bio-contact oxidation reactor (ABOR). With the supply of external power source 0.5 V in the UBER, AYR decolorization efficiency increased up to 94.8 ± 1.5%. Products formation efficiencies of p-phenylenediamine (PPD) and 5-aminosalicylic acid (5-ASA) were above 90% and 60%, respectively. Electron recovery efficiency based on AYR removal in cathode zone was nearly 100% at HRTs longer than 6 h. Relatively high concentration of AYR accumulated at higher AYR loading rates (>780 g m−3 d−1) likely inhibited acetate oxidation of anode-respiring bacteria on the anode, which decreased current density in the UBER; optimal AYR loading rate for the UBER was 680 g m−3 d−1 (HRT 2.5 h). The subsequent ABOR further improved effluent quality. Overall the Chroma decreased from 320 times to 80 times in the combined bio-system to meet the textile wastewater discharge standard II in China.

  11. Degradation of industrial azo dye in aqueous solution by heterogeneous Fenton process (fly ash/H2O2

    Directory of Open Access Journals (Sweden)

    Bečelić-Tomin Milena R.

    2012-01-01

    Full Text Available The aim of this study was to investigate the possibilities and efficiency of heterogeneous Fenton process with the use of fly ash from thermal power plants Kolubara, Serbia, as the catalyst in the degradation of industrial azo dye Zetanyl Rosso B-NG. The effects of various experimental parameters such as pH, temperature, concentration of fly ash, the initial concentration of H2O2 and initial concentration of dye on the kinetics and efficiency of decolorization were investigated. Simultaneous leaching of iron from fly ash was monitored. The optimum conditions had been determined, and it was found that decolorization efficiency obtained after 150 min of reaction, was about 98.9%. The optimal parameters were: initial pH = 3; [H2O2]0 = 6 mM; dosage of fly ash = 0.1g/l (for dye concentration of 100 mg/l; temperature = 22 °C. The effectiveness of the applied treatment for mineralization of dye solution was investigated, under optimal conditions determined by the examination of various factors influencing the decolorization process at the specified contact time. The maximum achieved reduction of total organic carbon content was 96.5%. The results indicate that the reuse of fly ash as the catalyst support in •OH production in this process achieves significant efficiency in terms of decolorization, 94.4% and mineralization, 89.6%. Futhermore, fly ash showed adequate stability during the reaction (low iron leaching, concentrations under optimal reaction condition were about 2 mg/l.

  12. Photocatalytic decolorization of azo-dye with zinc oxide powder in an external UV light irradiation slurry photoreactor

    International Nuclear Information System (INIS)

    Photocatalytic decolorization of azo-dye Orange II in water has been examined in an external UV light irradiation slurry photoreactor using zinc oxide (ZnO) as a semiconductor photocatalyst. The effects of process parameters such as light intensity, initial dye concentration, photocatalyst loading and initial solution pH on the decolorization rate of Orange II have been systematically investigated. A two-stage photocatalytic decolorization of Orange II, the first stage of fast decolorization rate and the subsequent second stage of rather slow decolorization rate, was found. The efficiency of decolorization of Orange II increased as initial Orange II concentration decreased and UV light intensity increased. There was the optimal ZnO concentration being around 1000 mg L-1. The optimal pH was around 7.7, which was at the natural pH of the dye solution. The effect of aeration rate on the decolorization of Orange II has been also investigated and the enhancement of decolorization of Orange II with increasing aeration rate was found. By using a model for the light intensity profile in the external UV light irradiation slurry photoreactor, the simulation model for the decolorization of Orange II with ZnO photocatalyst has been developed. The proposed model in which the slow decolorization in the second stage as well as the initial fast decolorization is also taken into account could simulate the experimental results for UV light irradiation satisfactorily. The proposed simulation model in which the change of light intensity with time due to the decolorization of Orange II and the light scatter due to solid photocatalysts are considered will be very useful for practical engineering design of the slurry photoreactor of wastewater including textile dyes

  13. Monopolar Electro-Coagulation Process for Azo Dye C.I. Acid Red 18 Removal from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Ghasem Azarian

    2014-12-01

    Full Text Available The discharge of wastewaters containing an untreated dye results in aesthetic problems and an increase in gases solubility, which causes light transmission inhibition into water bodies. In spite of advantages of physicochemical and biological methods, these processes produce huge amounts of sludge, toxic by-products and require several oxidant chemicals. By contrast, electrochemical processes because of their high versatility, high efficiency and eco-friendly properties are more acceptable. In the present study, the removal of azo dye Acid Red 18 and chemical oxygen demand (COD from synthetic wastewater by monopolar (EC process was investigated and key parameters such as operating time, current density (CD, initial pH and energy, and electrode consumption were optimized. It was found that the process had a very good efficiency in the removal of both COD and color; for the iron electrode, the maximum amounts of color and COD removal were 99.5% and 59.0%, respectively. An operating time of 45 min, pH of 7 and CD of 1.2 mA/cm2 was selected as the optimized condition. The optimization of variables is extremely crucial as it results in a decrease in costs, energy and electrode consumption. Overall, the iron electrode used less energy than the aluminum electrode and was more acceptable for use in this process due to economical reasons. The findings of UV/vis spectra illustrated that the structures of this dye were removed by the process. In comparison with traditional methods such as aerobic and anaerobic systems, the EC process is a suitable alternative for the treatment of wastewaters containing dye pollutants.

  14. Fast and efficient removal of alizarin yellow dye (Azo dye) from water and wastewater samples using modified nanoclay

    OpenAIRE

    Shahla Elhami; Hadis Drikvandi

    2014-01-01

    A fast and efficient method has been developed for removal of Alizarin Yellow dye using modified nanoclay. Montmorillonite (MMT) was modified by a facile and one-step procedure with diethylenetriamine (DETA) and was used as an adsorbent. The effects of pH value of the dye solution, adsorbent dose, adsorption time and the initial dye concentration on the Alizarin Yellow adsorption onto the composite were investigated.  The DETA-MMT had a high uptake capacity in room temperature and could remov...

  15. Low-temperature-fabricated ZnO, AZO, and SnO{sub 2} nanoparticle-based dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hong Hee; Park, Cheolmin; Choi, Wonkook; Cho, Sungjae; Moon, Byungjoon; Son, Dongick [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Yonsei University, Seoul (Korea, Republic of)

    2014-11-15

    The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO{sub 2} based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 .deg. C) dyesensitized ZnO, AZO, and SnO{sub 2} nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO{sub 2} nanoparticle layer which forms a nano porous ZnO, AZO, and SnO{sub 2} network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density (J{sub sc}), the open circuit potential (V{sub oc}), the fill factor (FF), and power conversion efficiency (η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm{sup 2}, 0.61 V, 0.46, and 1.43%, respectively.

  16. Low-temperature-fabricated ZnO, AZO, and SnO2 nanoparticle-based dye-sensitized solar cells

    International Nuclear Information System (INIS)

    The authors investigated the microstructural and the electrical properties of ZnO, AZO, and SnO2 based dye-sensitized solar cells (DSSCs) fabricated using a low-temperature-processed (200 .deg. C) dyesensitized ZnO, AZO, and SnO2 nanoparticle thin film and a Pt catalyst deposited on ITO/glass by RF magnetron sputtering. A hydropolymer containing PEG (poly ethylene glycol) and PEO (poly ethylene oxide) is used to make uniformly-distributed ZnO, AZO, and SnO2 nanoparticle layer which forms a nano porous ZnO, AZO, and SnO2 network after heat treatment. The layer is then dye sensitized and sandwiched between two electrodes in an electrolyte to make a DSSC device. The highest measured parameters, the short-circuit current density (Jsc), the open circuit potential (Voc), the fill factor (FF), and power conversion efficiency (η), of the DSSC fabricated wander optimized conditions were observed to be 5.10 mA/cm2, 0.61 V, 0.46, and 1.43%, respectively.

  17. Photocatalytic Removal of Azo Dye and Anthraquinone DyeUsing TiO2 Immobilised on Ceramic Tiles

    OpenAIRE

    P. N. Palanisamy; Kavitha, S. K.

    2011-01-01

    The photocatalytic activity of TiO2 immobilized on different supports; cement and ceramic tile, was studied to decolorize two commercial dyes. The catalyst was immobilised by two different techniques, namely, slurry method on ceramic tile and powder scattering on cement. The degradation of the dyes was carried out using UV and solar irradiation. The comparative efficiency of the catalyst immobilised on two different supports was determined. The photodegradation process was monitored by UV-Vis...

  18. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg-Cu-Y metallic glass powder through dealloying pretreatment

    Science.gov (United States)

    Luo, Xuekun; Li, Ran; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg65Cu25Y10 metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core-shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  19. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg–Cu–Y metallic glass powder through dealloying pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xuekun; Li, Ran, E-mail: liran@buaa.edu.cn; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao, E-mail: zhangtao@buaa.edu.cn

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg{sub 65}Cu{sub 25}Y{sub 10} metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core–shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  20. Adsorption of Azo-Dye Orange II from Aqueous Solutions Using a Metal-Organic Framework Material: Iron- Benzenetricarboxylate

    Directory of Open Access Journals (Sweden)

    Elizabeth Rojas García

    2014-12-01

    Full Text Available A Metal-Organic Framework (MOF, iron-benzenetricarboxylate (Fe(BTC, has been studied for the adsorptive removal of azo-dye Orange II from aqueous solutions, where the effect of various parameters was tested and isotherm and kinetic models were suggested. The adsorption capacities of Fe(BTC were much higher than those of an activated carbon. The experimental data can be best described by the Langmuir isotherm model (R2 > 0.997 and revealed the ability of Fe(BTC to adsorb 435 mg of Orange II per gram of adsorbent at the optimal conditions. The kinetics of Orange II adsorption followed a pseudo-second-order kinetic model, indicating the coexistence of physisorption and chemisorption, with intra-particle diffusion being the rate controlling step. The thermodynamic study revealed that the adsorption of Orange II was feasible, spontaneous and exothermic process (−25.53 kJ·mol−1. The high recovery of the dye showed that Fe(BTC can be employed as an effective and reusable adsorbent for the removal of Orange II from aqueous solutions and showed the economic interest of this adsorbent material for environmental purposes.

  1. Enhancement of the optical response in a biodegradable polymer/azo-dye film by the addition of carbon nanotubes

    International Nuclear Information System (INIS)

    A new biodegradable photoresponsive material was developed using poly(lactic acid) (PLA) as the matrix material and Disperse Orange 3 (DO3) as photoisomerizable azo-dye. It was observed that the addition of multi-walled carbon nanotubes (MWCNTs) leads to a new phenomenon consisting of an enhancement of the optical anisotropy in a wide range of temperatures. In particular, the optical anisotropy increases 100% at room temperature. Moreover, the material containing MWCNTs shows a faster optical response that is evidenced as an increase in the growth rate of optical anisotropy. Spectroscopic data is provided to study the interaction among DO3, MWCNTs and PLA. The enhancement of optical anisotropy obtained with the addition of MWCNTs was related to the glass transition temperature (Tg) of each material. Maximum optical anisotropy was obtained 15 °C below the Tg for both materials. Results are interpreted in terms of the interactions among DO3, MWCNTs and PLA and the packing density of the dye into the polymer chains. (paper)

  2. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg–Cu–Y metallic glass powder through dealloying pretreatment

    International Nuclear Information System (INIS)

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg65Cu25Y10 metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core–shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  3. Decolorization of sulfonated azo dye Metanil Yellow by newly isolated bacterial strains: Bacillus sp. strain AK1 and Lysinibacillus sp. strain AK2.

    Science.gov (United States)

    Anjaneya, O; Souche, S Yogesh; Santoshkumar, M; Karegoudar, T B

    2011-06-15

    Two different bacterial strains capable of decolorizing a highly water soluble azo dye Metanil Yellow were isolated from dye contaminated soil sample collected from Atul Dyeing Industry, Bellary, India. The individual bacterial strains Bacillus sp. AK1 and Lysinibacillus sp. AK2 decolorized Metanil Yellow (200 mg L(-1)) completely within 27 and 12h respectively. Various parameters like pH, temperature, NaCl and initial dye concentrations were optimized to develop an economically feasible decolorization process. The maximum concentration of Metanil Yellow (1000 mg L(-1)) was decolorized by strains AK2 and AK1 within 78 and 84 h respectively. These strains could decolorize Metanil Yellow over a broad pH range 5.5-9.0; the optimum pH was 7.2. The decolorization of Metanil Yellow was most efficient at 40°C and confirmed by UV-visible spectroscopy, TLC, HPLC and GC/MS analysis. Further, both the strains showed the involvement of azoreductase in the decolorization process. Phytotoxicity studies of catabolic products of Metanil Yellow on the seeds of chick pea and pigeon pea revealed much reduction in the toxicity of metabolites as compared to the parent dye. These results indicating the effectiveness of strains AK1 and AK2 for the treatment of textile effluents containing azo dyes. PMID:21470774

  4. Solid phase extraction using silica gel modified with azo-dyes derivative for preconcentration and separation of Th(IV) ions from aqueous solutions

    International Nuclear Information System (INIS)

    Azo-dyes derivative (HL) sorbent was synthesized according to the literature to be used in the adsorption and preconcentration of Th(IV) ions from aqueous solution and it was exposed to immobilization, and new solid support material was obtained. For this purpose, azo-dyes derivative (HL) was chemically bonded to silica gel surface immobilized 3-chloropropyl trimethoxysilane, then analyzed by FTIR, BET, SEM and elemental analysis. The influence of the solution pH, initial Th(IV) concentration, amount of sorbent, contact time, temperature and foreign ion effect was investigated. The maximum Th(IV) uptake capacity was found to be 24.85 ± 0.2 mg/g. (author)

  5. A comparative study of selected disperse azo dye derivatives based on spectroscopic (FT-IR, NMR and UV-Vis) and nonlinear optical behaviors

    Science.gov (United States)

    Cinar, Mehmet; Coruh, Ali; Karabacak, Mehmet

    2014-03-01

    In the present work, a combined experimental and quantum chemical study on ground state equilibrium structure, spectroscopic and nonlinear optical properties of selected disperse azo dye molecules are reported. The vibrational transitions were identified based on the recorded FT-IR spectra in the range of 4000-400 cm-1 for solid state, simulated IR spectra and total energy distribution (TED) of vibrational modes. The chemical shifts were determined from the results of observed 1H and 13C NMR spectra in chloroform and dimethylsulfoxide solution. The DFT/gauge-invariant atomic orbital (GIAO) methodology was applied to predict the magnetic properties. Electronic properties were carried out by UV-Vis spectroscopy and TD-DFT/CIS approach. The nonlinear optical (NLO) features were addressed theoretically. A detailed description of spectroscopic and NLO behaviors of studied disperse azo dyes was reported with the help of comparison of experimental measurements and theoretical calculations.

  6. Heterogeneous fenton-like degradation of an azo dye reactive brilliant orange by the combination of activated carbon-FeOOH catalyst and H 2O2

    DEFF Research Database (Denmark)

    Wu, Jinhua; Lin, Guanghui; Li, Ping;

    2013-01-01

    The decoloration of an azo dye reactive brilliant orange (X-GN) by a heterogeneous Fenton system using activated carbon-FeOOH catalyst (AC-FeOOH) and H2O2 was studied. Under typical conditions (pH 7.0, H2O2 10 mmol/L, AC-FeOOH 1.0g/L and 30°C), 98% decoloration rate of X-GN was achieved in 240 mm...

  7. Synthesis, structural characterization, and antimicrobial efficiency of sulfadiazine azo-azomethine dyes and their bi-homonuclear uranyl complexes for chemotherapeutic use

    OpenAIRE

    Khedr, Abdalla M.; SAAD, FAWAZ A.

    2015-01-01

    Two sulfadiazine azo-azomethine dyes containing two active coordination centers and their bi-homonuclear UO_2(II)-complexes were synthesized for potential chemotherapeutic use. The ligands were prepared, starting from the coupling of sulfadiazine dizonium salt with acetylacetone, followed by condensation with ethylenediamine and 1,6-hexanediamine (HL^I and HL^{II}) using a modified literature procedure. The structures of the ligands and their UO_2(II)-complexes were elucidated by conve...

  8. CYP-dependent induction of glutathione S-transferase in Daphnia similis exposed to a disperse azo dye.

    Science.gov (United States)

    Yu, Tsai Hsin; Dafre, Alcir Luiz; de Aragão Umbuzeiro, Gisela; Franciscon, Elisangela

    2015-01-01

    Disperse Red 1 (DR1) is an azo dye that can reach the aquatic environment through the discharge of textile industrial wastewaters. It has been tested in Daphnia similis and shown to be highly toxic. Cytochrome P450 (CYP) is a class of enzymes involved in phase I of detoxification, while glutathione S-transferase (GST) are a class of phase II enzymes. No information about phase I or II dye metabolism in microcrustacea were found in the literature. In this study we identified CYP and GST enzymes involved in the metabolism of DR1 in juveniles of D. similis. Using spectrophotometric analysis we showed that 50 % of the dye was absorbed by the organisms, which could be confirmed by the reddish color of animals exposed to DR1, however adsorption cannot be ruled out. GST activity increased from 280 to 615 nmol(-1 )min(-1 )mg when D. similis were exposed for 48 h to 0.2 mg L(-1) DR1 and from 274 to 815 nmol(-1) min(-1 )mg when exposed to 5 mg L(-1). Data clearly demonstrate that exposure to DR1 can stimulate a strong induction of GST activity, whose participation in DR1 metabolism needs to be confirmed. The induction of GST activity seems to be dependent on CYP activity, since treatment with SKF535A, a CYP inhibitor, blocked the DR1-dependent GST induction. We speculate that GST is involved in DR1 metabolism in Daphnia and that CYP activity is necessary to induce GST-activity, which is an indirect evidence of its role in the biotransformation of DR1. PMID:25218178

  9. The radiation-induced decoloration of azo dye in aqueous solutions

    International Nuclear Information System (INIS)

    The decoloration yield of an Acid Red 265 neutral aqueous solution, G(-Dye), equaled 1.00+-0.04, regardless of the dose rate and the initial dye concentration in the early stage. The G(-Dye) increased to 1.46 in the presence of nitrous oxide, but was independent of the presence of oxygen and acetone. In nitrogen-saturated solutions, the G(-Dye) increased markedly upon the addition of alcohols - for example, up to 1.83 upon the addition of 2 mM n-butyl alcohol. On the other hand, in oxygen-saturated solutions, the G(-Dye) decreased markedly upon the addition of even a small amount of alcohols. The effects of alcohols, namely, the G(-Dye) in both the solutions were in the order of their reactivity with OH radicals. The decoloration is attributable to the attack of the OH radicals formed by the radiolysis of water to the dye. The increase in the G(-Dye) for the nitrogen-saturated solutions containing alcohols is attributable to the attack of the alcohol radicals (RC HOH)( : radical) formed by the reactions of alcohols with OH radicals. In the oxygen-saturated solutions, the RC HOH radicals are converted to the peroxides, which do not react with the dye. The rate constant for the reaction of the OH radical with Acid Red 265, obtained by using various additives from the competition reaction method, is 9.3+-1.4x109 M-1 s-1. The effects of CNS-, glucose, and phenol were also examined. (auth.)

  10. Role of surfactant derived intermediates in the efficacy and mechanism for radiation chemical degradation of a hydrophobic azo dye, 1-phenylazo-2-naphthol

    Energy Technology Data Exchange (ETDEWEB)

    Das, Laboni [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chatterjee, Suchandra [Food Technology Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Naik, Devidas B. [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Adhikari, Soumyakanti, E-mail: asoumya@barc.gov.in [Radiation & Photochemistry Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2015-11-15

    Highlights: • Demonstration of the role of surfactant in the degradation of the hydrophobic dye. • First direct observation of the formation of “hydrazyl radical-parent” adduct. • Similar products obtained in the reaction of e{sup −}{sub aq} and ·OH radical in TX-100 medium. • Significant reduction in cytotoxicity of irradiated dye in aqueous–organic medium. • New mechanistic pathway could be delineated. - Abstract: A combined methodology involving gamma and pulse radiolysis, product analysis and toxicity studies has been adopted to comprehend the degradation process of a model hydrophobic azo dye, 1-phenylazo-2-naphthol, emphasizing the role of the surfactant, which is an integral part of textile waste. Two new and important findings are underlined in this article. The first is the direct attestation of the hydrazyl radical-parent adduct, formed in the reaction of the dye with e{sup −}{sub aq} followed by protonation and subsequent addition to the unreacted dye molecule. This has been confirmed from concentration dependent studies. Secondly, we have clearly shown that in the reaction of hydroxyl radical with the dye in Triton X-100 media, the initially produced TX radicals cause reductive degradation of the dye. Identification and detailed analysis of HPLC and GCMS data reveals that similar products are formed in both the reactions of e{sup −}{sub aq} and ·OH radicals. Moreover, the cytotoxicity of 10{sup −4} mol dm{sup −3} dye was found to be reduced significantly after irradiation. Thus, the present study not only depicts new pathways for the degradation of hydrophobic azo dye, but also demonstrates the role of a surfactant in the entire process.

  11. Role of surfactant derived intermediates in the efficacy and mechanism for radiation chemical degradation of a hydrophobic azo dye, 1-phenylazo-2-naphthol

    International Nuclear Information System (INIS)

    Highlights: • Demonstration of the role of surfactant in the degradation of the hydrophobic dye. • First direct observation of the formation of “hydrazyl radical-parent” adduct. • Similar products obtained in the reaction of e−aq and ·OH radical in TX-100 medium. • Significant reduction in cytotoxicity of irradiated dye in aqueous–organic medium. • New mechanistic pathway could be delineated. - Abstract: A combined methodology involving gamma and pulse radiolysis, product analysis and toxicity studies has been adopted to comprehend the degradation process of a model hydrophobic azo dye, 1-phenylazo-2-naphthol, emphasizing the role of the surfactant, which is an integral part of textile waste. Two new and important findings are underlined in this article. The first is the direct attestation of the hydrazyl radical-parent adduct, formed in the reaction of the dye with e−aq followed by protonation and subsequent addition to the unreacted dye molecule. This has been confirmed from concentration dependent studies. Secondly, we have clearly shown that in the reaction of hydroxyl radical with the dye in Triton X-100 media, the initially produced TX radicals cause reductive degradation of the dye. Identification and detailed analysis of HPLC and GCMS data reveals that similar products are formed in both the reactions of e−aq and ·OH radicals. Moreover, the cytotoxicity of 10−4 mol dm−3 dye was found to be reduced significantly after irradiation. Thus, the present study not only depicts new pathways for the degradation of hydrophobic azo dye, but also demonstrates the role of a surfactant in the entire process

  12. Adsorption of Reactive Red 198 Azo Dye fromAqueous Solution onto theWaste Coagulation Sludge of theWater Treatment Plants

    OpenAIRE

    Mahmoudi, M; G.R Moussavi; H. Asilian

    2010-01-01

    "n "n "nBackgrounds and Objectives:Much attention has been recently paid on using waste materials as adsorbents for removal of contaminants from water and wastewater. A new low cost waste was examined for its capacity to adsorb RR198, an azo reactive model dye, from an aqueous solution."nMaterials andMethods: The waste was dried, powdered and characterized before being used as an adsorbent. The effects of pH (3-10), adsorbent dose (0.2-3 g), dye concentration and contact time on the adsorptio...

  13. Effect of electrode position on azo dye removal in an up-flow hybrid anaerobic digestion reactor with built-in bioelectrochemical system

    OpenAIRE

    Cui, Min-Hua; Cui, Dan; Lee, Hyung-Sool; Liang, Bin; Wang, Ai-Jie; Cheng, Hao-Yi

    2016-01-01

    In this study, two modes of hybrid anaerobic digestion (AD) bioreactor with built-in BESs (electrodes installed in liquid phase (R1) and sludge phase (R2)) were tested for identifying the effect of electrodes position on azo dye wastewater treatment. Alizarin yellow R (AYR) was used as a model dye. Decolorization efficiency of R1 was 90.41 ± 6.20% at influent loading rate of 800 g-AYR/ m3·d, which was 39% higher than that of R2. The contribution of bioelectrochemical reduction to AYR decolori...

  14. ESTIMATION OF IONIZATION CONSTANTS OF AZO DYES AND RELATED AROMATIC AMINES: ENVIRONMENTAL IMPLICATIONS

    Science.gov (United States)

    Ionization constants for 214 dye molecules were calculated from molecular structures using the chemical reactivity models developed in SPARC (SPARC Performs Automated Reasoning in Chemistry). hese models used fundamental chemical structure theory to predict chemical reactivities ...

  15. TiO2/Ag modified penta-bismuth hepta-oxide nitrate and its adsorption performance for azo dye removal

    Institute of Scientific and Technical Information of China (English)

    Eshraq Ahmed Abdullah; Abdul Halim Abdullah; Zulkarnain Zainal; Mohd Zobir Hussein; Tan Kar Ban

    2012-01-01

    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents.The synthesized product was characterized by different analytical techniques.The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants.Different kinetic,isotherm and diffusion models were chosen to describe the adsorption process.X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however,the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes.Dyes removal was found to be a function of adsorbent dosage,initial dye concentration,solution pH and temperature.The reduction of Langrnuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent.Mass transfer can be described by intra-particle diffusion at a certain stage,but it was not the rate limiting step that controlled the adsorption process.Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.

  16. Comparison of three combined sequencing batch reactor followed by enhanced Fenton process for an azo dye degradation: Bio-decolorization kinetics study.

    Science.gov (United States)

    Azizi, A; Alavi Moghaddam, M R; Maknoon, R; Kowsari, E

    2015-12-15

    The purpose of this research was to compare three combined sequencing batch reactor (SBR) - Fenton processes as post-treatment for the treatment of azo dye Acid Red 18 (AR18). Three combined treatment systems (CTS1, CTS2 and CTS3) were operated to investigate the biomass concentration, COD removal, AR18 dye decolorization and kinetics study. The MLSS concentration of CTS2 reached 7200 mg/L due to the use of external feeding in the SBR reactor of CTS2. The COD concentration remained 273 mg/L and 95 mg/L (initial COD=3270 mg/L) at the end of alternating anaerobic-aerobic SBR with external feeding (An-A MSBR) and CTS2, respectively, resulting in almost 65% of Fenton process efficiency. The dye concentration of 500 mg/L was finally reduced to less than 10mg/L in all systems indicating almost complete AR18 decolorization, which was also confirmed by UV-vis analysis. The dye was removed following two successive parts as parts 1 and 2 with pseudo zero-order and pseudo first-order kinetics, respectively, in all CTSs. Higher intermediate metabolites degradation was obtained using HPLC analysis in CTS2. Accordingly, a combined treatment system can be proposed as an appropriate and environmentally-friendly system for the treatment of the azo dye AR18 in wastewater. PMID:26143197

  17. Synthesis of some transition metal complexes with new heterocyclic thiazolyl azo dye and their uses as sensitizers in photo reactions

    Science.gov (United States)

    AL-Adilee, Khalid J.; Abass, Ahmed K.; Taher, Ali M.

    2016-03-01

    A new heterocyclic thiazolylazo dye ligand, 2- [bar2-(4, 5- dimethyl thiazolyl) azo ] -4-Ethoxy Phenol (DMeTAEP), (LH) was synthesized by the diazotization of 4.5-dimethyl thiazolylazonium chloride and coupling with 4- Ethoxy phenol in alkaline alcoholic solution under suitable optimized experimental conditions to yield a new azo dye ligand. The structure of ligand and its complexes was prepared from Co(III), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II), Ag (I) and Au(III) ions. They confirmed by XRD, SEM, (TG-DTG) thermal analysis, 1H-NMR,UV-visb, mass and FT-IR spectroscopic methods, elemental analysis, atomic absorption, magnetic susceptibility and molar conductance. The mole ratio [M: L], it was also studied which was 1:1 for Ag (I) and Au (III) complexes and 1:2 The rest of the metal complexes. The isolated solid complexes are found to have the general formula [M (L)2 ] Cln.mH2O, where n = 1, m = 0 when M = Co (III) and n = 0, m = 1 when M = Ni (II), and Hg(II) while n = 0 and m = 0 when M = Cu (II), Zn (II), Cd (II) and ]ML (H2O)] of Ag(I) - complex but Au(III)-complex structural formula was [Au(L)Cl] Cl conductivity measurements for prepared complexes showed 1:1 electrolyte for Co(III(and Au(III) complexes and non - electrolyte the rest of complexes. The spectral and analytical data revealed that this ligand behaves as a tridentate chelating agent and coordination number of all metal ions were found to be six except for Ag (I) and Au (III) which was four. The activities of complexes were examined as sensitizers in the photocatalytic reaction of p-nitro aniline (PNA) which is used as a model of water pollutants.

  18. Novel 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3Hone-6-sulphonic acidbased mono azo reactive dyes

    Directory of Open Access Journals (Sweden)

    DIVYESH R. PATEL

    2011-02-01

    Full Text Available A series of new heterocyclic mono azo reactive dyes 7a–m were prepared by diazotization of 2-phenyl-3-{4’-[N-(4”-aminophenylcarbamoyl]-phenyl}-quinazoline-4(3H-one-6-sulphonic acid (3 and coupling with various cyanurated coupling components 6a–m and their dyeing performance on silk, wool and cotton fibres was assessed. These dyes were found to give a variety of colour shades with very good depth and levelness on the fibres. All the compounds were identified by conventional method (IR and 1H-NMR and elemental analyses. The percentage dye bath exhaustion on different fibres was reasonably good and acceptable. The dyed fibre showed moderate to very good fastness to light, washing and rubbing.

  19. Effect of an azo dye on the performance of an aerobic granular sludge sequencing batch reactor treating a simulated textile wastewater.

    Science.gov (United States)

    Franca, Rita D G; Vieira, Anabela; Mata, Ana M T; Carvalho, Gilda S; Pinheiro, Helena M; Lourenço, Nídia D

    2015-11-15

    This study analyzed the effect of an azo dye (Acid Red 14) on the performance of an aerobic granular sludge (AGS) sequencing batch reactor (SBR) system operated with 6-h anaerobic-aerobic cycles for the treatment of a synthetic textile wastewater. In this sense, two SBRs inoculated with AGS from a domestic wastewater treatment plant were run in parallel, being one supplied with the dye and the other used as a dye-free control. The AGS successfully adapted to the new hydrodynamic conditions forming smaller, denser granules in both reactors, with optimal sludge volume index values of 19 and 17 mL g(-1) after 5-min and 30-min settling, respectively. As a result, high biomass concentration levels and sludge age values were registered, up to 13 gTSS L(-1) and 40 days, respectively, when deliberate biomass wastage was limited to the sampling needs. Stable dye removal yields above 90% were attained during the anaerobic reaction phase, confirmed by the formation of one of the aromatic amines arising from azo bond reduction. The control of the sludge retention time (SRT) to 15 days triggered a 30% reduction in the biodecolorization yield. However, the increase of the SRT values back to levels above 25 days reverted this effect and also promoted the complete bioconversion of the identified aromatic amine during the aerobic reaction phase. The dye and its breakdown products did not negatively affect the treatment performance, as organic load removal yields higher than 80% were attained in both reactors, up to 77% occurring in the anaerobic phase. These high anaerobic organic removal levels were correlated to an increase of Defluviicoccus-related glycogen accumulating organisms in the biomass. Also, the capacity of the system to deal with shocks of high dye concentration and organic load was successfully demonstrated. Granule breakup after long-term operation only occurred in the dye-free control SBR, suggesting that the azo dye plays an important role in improving granule

  20. Comparative study of toxicity of azo dye Procion Red MX-5B following biosorption and biodegradation treatments with the fungi Aspergillus niger and Aspergillus terreus.

    Science.gov (United States)

    Almeida, E J R; Corso, C R

    2014-10-01

    Azo dyes are an important class of environmental contaminants and are characterized by the presence of one or more azo bonds (-N=N-) in their molecular structure. Effluents containing these compounds resist many types of treatments due to their molecular complexity. Therefore, alternative treatments, such as biosorption and biodegradation, have been widely studied to solve the problems caused by these substances, such as their harmful effects on the environment and organisms. The aim of the present study was to evaluate biosorption and biodegradation of the azo dye Procion Red MX-5B in solutions with the filamentous fungi Aspergillus niger and Aspergillus terreus. Decolorization tests were performed, followed by acute toxicity tests using Lactuca sativa seeds and Artemia salina larvae. Thirty percent dye removal of the solutions was achieved after 3 h of biosorption. UV-Vis spectroscopy revealed that removal of the dye molecules occurred without major molecular changes. The acute toxicity tests confirmed lack of molecular degradation following biosorption with A. niger, as toxicity to L. sativa seed reduced from 5% to 0%. For A. salina larvae, the solutions were nontoxic before and after treatment. In the biodegradation study with the fungus A. terreus, UV-Vis and FTIR spectroscopy revealed molecular degradation and the formation of secondary metabolites, such as primary and secondary amines. The biodegradation of the dye molecules was evaluated after 24, 240 and 336 h of treatment. The fungal biomass demonstrated considerable affinity for Procion Red MX-5B, achieving approximately 100% decolorization of the solutions by the end of treatment. However, the solutions resulting from this treatment exhibited a significant increase in toxicity, inhibiting the growth of L. sativa seeds by 43% and leading to a 100% mortality rate among the A. salina larvae. Based on the present findings, biodegradation was effective in the decolorization of the samples, but generated

  1. Characterization of azo dyes on Pt and Pt/polyaniline/dispersed Pt electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Molina, J.; Fernandez, J.; Rio, A.I. del; Bonastre, J. [Departamento de Ingenieria Textil y Papelera, EPS de Alcoy, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell s/n, 03801 Alcoy (Spain); Cases, F., E-mail: fjcases@txp.upv.es [Departamento de Ingenieria Textil y Papelera, EPS de Alcoy, Universitat Politecnica de Valencia, Plaza Ferrandiz y Carbonell s/n, 03801 Alcoy (Spain)

    2012-06-15

    The electrochemical characterization of two organic dyes (amaranth and procion orange MX-2R) has been performed on Pt electrodes and Pt electrodes coated with polyaniline and dispersed Pt. Electrodes with different Pt loads have been synthesized and characterized obtaining that a load of 300 {mu}g cm{sup -2} was the optimum one. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) was employed to observe the distribution and morphology of the Pt nanoparticles. The electroactivity of the electrodes has also been characterized by means of scanning electrochemical microscopy (SECM). The chemical characterization of Pt dispersed Pani coated Pt electrodes (Pt-Pani-Pt) was performed by means of X-ray photoelectron spectroscopy (XPS). The electrochemical characterization of the dyes has been performed by means of cyclic voltammetry. Voltammograms have shown that the presence of the dyes diminishes characteristic Pt oxidation and reduction peaks. However, redox processes due to the dyes, appeared in the voltammograms. The different species responsible of these redox processes were generated in the vicinity of the electrode and were not adsorbed on the electrode surface since after stirring, the different redox processes disappeared. Characterization with different scan rates showed that redox processes of both dyes were controlled by diffusion.

  2. Graphene oxide supported copper oxide nanoneedles: An efficient hybrid material for removal of toxic azo dyes.

    Science.gov (United States)

    Rajesh, Rajendiran; Iyer, Sahithya S; Ezhilan, Jayabal; Kumar, S Senthil; Venkatesan, Rengarajan

    2016-09-01

    Herein, we report a simple, one step synthesis of hybrid copper oxide nanoneedles on graphene oxide sheets (GO-CuONNs) through sonochemical method. The present method affords a facile mean for controlling effective concentration of the active CuO nanoneedles on the graphene oxide sheets, and also offers the necessary stability to the resulting GO-CuONNs structure for adsorption transformations.Furthermore, this hybrid GO-CuONNs is successfully employed in the removal of a series of hazardous ionic organic dyes namely coomassie brilliant blue, methylene blue, congo red and amidoblack 10B. Through careful investigation of the material, we found that the synergetic effect between CuONNs and GO play a significant role in the adsorption of all the dyes studied. The prepared hybrid material contains both hydrophobic and hydrophilic environment which is expected to enhance the electrostatic interaction between the adsorbent and the dye molecules, consequently favouring the adsorption process. PMID:27208759

  3. Graphene oxide supported copper oxide nanoneedles: An efficient hybrid material for removal of toxic azo dyes

    Science.gov (United States)

    Rajesh, Rajendiran; Iyer, Sahithya S.; Ezhilan, Jayabal; Kumar, S. Senthil; Venkatesan, Rengarajan

    2016-09-01

    Herein, we report a simple, one step synthesis of hybrid copper oxide nanoneedles on graphene oxide sheets (GO-CuONNs) through sonochemical method. The present method affords a facile mean for controlling effective concentration of the active CuO nanoneedles on the graphene oxide sheets, and also offers the necessary stability to the resulting GO-CuONNs structure for adsorption transformations.Furthermore, this hybrid GO-CuONNs is successfully employed in the removal of a series of hazardous ionic organic dyes namely coomassie brilliant blue, methylene blue, congo red and amidoblack 10B. Through careful investigation of the material, we found that the synergetic effect between CuONNs and GO play a significant role in the adsorption of all the dyes studied. The prepared hybrid material contains both hydrophobic and hydrophilic environment which is expected to enhance the electrostatic interaction between the adsorbent and the dye molecules, consequently favouring the adsorption process.

  4. Evaluation of three reagent dosing strategies in a photo-Fenton process for the decolorization of azo dye mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Prato-Garcia, D. [Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingenieria, Unidad Academica Juriquilla, Universidad Nacional Autonoma de Mexico, Blvd. Juriquilla 3001, Queretaro 76230 (Mexico); Buitron, German, E-mail: gbuitronm@iingen.unam.mx [Laboratory for Research on Advanced Processes for Water Treatment, Instituto de Ingenieria, Unidad Academica Juriquilla, Universidad Nacional Autonoma de Mexico, Blvd. Juriquilla 3001, Queretaro 76230 (Mexico)

    2012-05-30

    Highlights: Black-Right-Pointing-Pointer Dosing strategies for a photo-Fenton process were evaluated. Black-Right-Pointing-Pointer The dosing strategy had no effect of on the decolorization. Black-Right-Pointing-Pointer The type of strategy influenced SUVA index, toxicity reduction and biodegradability. Black-Right-Pointing-Pointer A continuous reagents supply was found to be the most adequate strategy. Black-Right-Pointing-Pointer Decolorization as well as a less toxic and biodegradable effluent was produced. - Abstract: Three reagent dosing strategies used in the solar photo-assisted decolorization of a mixture of sulfonated dyes consisting of acid blue 113, acid orange 7 and acid red 151 were evaluated. Results demonstrated that the dosing strategy influenced both reagent consumption and the biodegradability and toxicity of the effluent. In one strategy (E{sub 1}), the Fenton's reactants were dosed in a punctual mode, while in the other two strategies (E{sub 2} an E{sub 3}), the reactants were dosed continuously. In the E{sub 2} strategy the reactants were dosed by varying the duration of the injection time. In the E{sub 3} strategy, the reactants were dosed during 60 min at a constant rate, but with different concentrations. All cases showed that feeding the reactor between 40% and 60% of the maximal dose was sufficient to decolorize more than 90% of the mixture of azo dyes. The E{sub 1} strategy was less effective for aromatic content reduction. Conversely, the continuous addition of the reagents (E{sub 2} and E{sub 3} strategies) improved the aromatic content removal. E{sub 3} strategy was substantially more appropriate than E{sub 1} strategy due to improved the effluent quality in two key areas: toxicity and biodegradability.

  5. Use of active consortia of constructed ternary bacterial cultures via mixture design for azo-dye decolorization enhancement

    International Nuclear Information System (INIS)

    This first-attempt study used constructed bacterial consortia containing Escherichia coli DH5α (a weak decolorizer) and its UV-irradiated mutants (E. coli UVT1 and UV68; strong decolorizers) via equilateral triangle diagram and mixture experimental design to assess color removal during species evolution. The results showed that although strain DH5α was not an effective decolorizer, its presence might still played a significant role in affecting optimal color removal capabilities of mixed consortia (e.g., E. coli DH5α, UVT1 and UV68) for two model azo dyes; namely, reactive red 22 (RR22) and reactive black 5 (RB5). Contour analysis of ternary systems also clearly showed that decolorization of RR22 and RB5 by DH5α-containing active mixed consortia was more effective than mono-cultures of the stronger decolorizer alone (e.g., UVT1). The optimal composition of the mixed consortium (UV68, UVT1, DH5α) achieving the highest specific decolorization rate was (13%:58%:29%) and (0%:74%:26%) for decolorization of RR22 and RB5, respectively, with initial total cell density fixed at OD600 = 3.5 ± 0.28

  6. Steady performance of a zero valent iron packed anaerobic reactor for azo dye wastewater treatment under variable influent quality

    Institute of Scientific and Technical Information of China (English)

    Yaobin Zhang; Yiwen Liu; Yanwen Jing; Zhiqiang Zhao; Xie Quan

    2012-01-01

    Zero valent iron (ZVI) is expected to help create an enhanced anaerobic environment that might improve the performance of anaerobic treatment.Based on this idea,a novel ZVI packed upflow anaerobic sludge blanket (ZVI-UASB) reactor was developed to treat azo dye wastewater with variable influent quality.The results showed that the reactor was less influenced by increases of Reactive Brilliant Red X-3B concentration from 50 to 1000 mg/L and chemical oxygen demand (COD) from 1000 to 7000 mg/L in the feed than a reference UASB reactor without the ZVI.The ZVI decreased oxidation-reduction potential in the reactor by about 80 mV.Iron ion dissolution from the ZVI could buffer acidity in the reactor,the amount of which was related to the COD concentration.Fluorescence in situ hybridization test showed the abundance of methanogens in the sludge of the ZVI-UASB reactor was significantly greater than that of the reference one.Denaturing gradient gel electrophoresis showed that the ZVI increased the diversity of microbial strains responsible for high efficiency.

  7. Decoloration of Azo Dye Sunset Yellow by a Coaxial Insulated-Rod-to-Cylinder Underwater Streamer Discharge System

    Institute of Scientific and Technical Information of China (English)

    温小琼; 王明; 丁振峰; 刘贵师

    2012-01-01

    A coaxial insulated-rod-to-cylinder underwater streamer discharge system capable of injecting plasma into a large volume of water was developed and employed to decolorize azo dye sunset yellow. The rod type anode was covered by an insulator tube with a wall thickness of 0.4 mm. A series of slits with a width of 20 μm to 80 μm and a length of about 4 mm were cut onto the wall of the insulator tube. Depending on the solution conductivity, a cylindrical discharge region with a length of 60 mm and a wall thickness of 5 mm to 11 mm forms in the reactor. The influence of the solution conductivity, pH and pulse frequency on the decoloration of sunset yellow was investigated. The results show that the solution conductivity has little effect, while the solution pH and the pulse frequency have significant influence on the decoloration rate of sunset yellow. The decoloration rate of sunset yellow is increased with the increase in pulse frequency. A lower pH in solution promotes the decoloration of sunset yellow while a higher pH inhibits it.

  8. Decoloration of Azo Dye Sunset Yellow by a Coaxial Insulated-Rod-to-Cylinder Underwater Streamer Discharge System

    International Nuclear Information System (INIS)

    A coaxial insulated-rod-to-cylinder underwater streamer discharge system capable of injecting plasma into a large volume of water was developed and employed to decolorize azo dye sunset yellow. The rod type anode was covered by an insulator tube with a wall thickness of 0.4 mm. A series of slits with a width of 20 μm to 80 μm and a length of about 4 mm were cut onto the wall of the insulator tube. Depending on the solution conductivity, a cylindrical discharge region with a length of 60 mm and a wall thickness of 5 mm to 11 mm forms in the reactor. The influence of the solution conductivity, pH and pulse frequency on the decoloration of sunset yellow was investigated. The results show that the solution conductivity has little effect, while the solution pH and the pulse frequency have significant influence on the decoloration rate of sunset yellow. The decoloration rate of sunset yellow is increased with the increase in pulse frequency. A lower pH in solution promotes the decoloration of sunset yellow while a higher pH inhibits it.

  9. Development of a polyoxometallate-based photocatalyst assembled with cucurbit[6]uril via hydrogen bonds for azo dyes degradation

    International Nuclear Information System (INIS)

    Graphical abstract: A novel photocatalyst assembled from α-Keggin type polyoxometallate and macrocycle cucurbit[6]uril via hydrogen bonding has been synthesized and exhibits good photocatalytic activity towards azo dyes degradation. - Abstract: A water insoluble cucurbit[6]uril-polyoxometallates (CB[6]-POMs) composite assembled from α-Keggin type polysilicontungstate anions and macrocycle cucurbit[6]uril (CB[6]) via hydrogen bonding has been synthesized as visible light active photocatalyst. The physical and photocatalytic properties of such photocatalyst have been fully characterized by PXRD, FTIR, TG, XPS, and UV/vis diffuse reflectance spectra. The catalyst shows a good photocatalytic activity towards the degradation of methyl orange (MO) under visible light irradiation and displays good reproducibility of photocatalytic degradation by a simple recycled procedure without obvious loss in catalytic activity, which is of great significance for practical use of the photocatalyst. In the photodegradation process, the {Ni-CB[6]}n chain of the photocatalyst acts as sensitizer and can be induced by visible light, meanwhile the POMs chain of the photocatalyst acts as electron acceptor and deposits the electron in its LUMO. The effects of various experimental parameters and the proposed mechanisms are discussed in detail.

  10. Plant-mediated synthesis of silver-nanocomposite as novel effective azo dye adsorbent

    Science.gov (United States)

    Satapathy, Mantosh Kumar; Banerjee, Priya; Das, Papita

    2015-01-01

    Toxicity of textile effluent is a globally alarming issue nowadays. In order to address this problem, a cost-effective and environment-friendly technique for adsorption of toxic dyes has been introduced in this research. Firstly in this study, green synthesis of silver nanoparticles (AgNPs) having antibacterial efficacy, had been carried out using leaf extracts of Azadirachta indica as reducing as well as capping agent. This research idea was further extended for the development and application of a novel method of preparation of silver-nanocomposite using synthesized microwave-assisted AgNPs with soil as a novel nanocomposite to adsorb hazardous dyes. However, this nanocomposite was found to possess higher efficiency and adsorption capacity in comparison to soil as adsorbent for the removal of crystal violet dye under same experimental conditions. Additionally, it was also observed that use of this Ag-nanocomposite as adsorbent helped in achieving about 97.2 % removal of crystal violet dye from the effluent solution.

  11. AZO DYES ARE MAJOR CONTRIBUTORS TO THE MUTAGENIC ACTIVITY DETECTED IN THE CRISTAIS RIVER WATERS

    Science.gov (United States)

    To determine if compounds from a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a Drinking Water T...

  12. THE CONTRIBUTION OF AZO DYES TO THE MUTAGENIC ACTIVITY OF THE CRISTAIS RIVER

    Science.gov (United States)

    To verify if compounds within the discharge of a dye processing plant were contributing to the mutagenicity repeatedly found in the Cristais River, Sao Paulo, Brazil, we chemically characterized the treated industrial effluent, raw and treated water, and the sludge produced by a ...

  13. Synthesis, structural elucidation, solvatochromism and spectroscopic properties of some azo dyes derived from 6-chloro-4-hydroxyquinoline-2(1H)-one

    Science.gov (United States)

    Rufchahi, E. O. Moradi; Gilani, A. Ghanadzadeh; Taghvaei, V.; Karimi, R.; Ramezanzade, N.

    2016-03-01

    Malondianilide (I) derived from p-chloroaniline was cyclized to 6-chloro-4-hydroxyquinoline-2(1H)-one (II) in moderately good yield using polyphosphoric acid as catalyst. This compound was then coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes 1-12. A systematic study of the effect of solvent, acid, base and pH upon the electronic absorption spectra of the dyes 1-12 was carried out. In DMSO, DMF, CH3CN, CHCl3, EtOH and acidic media (CH3COOH, acidified EtOH) these dyes that theoretically may be involved in azo-hydrazone tautomerism have been detected only as hydrazone tautomers T1 and T2. The acidic dissociation constants of the dyes were measured in 80 vol% ethanol-water solution at room temperature and ionic strength of 0.1. The results were correlated by the Hammett-type equation using the substituent constants σx.

  14. Optimization and modelling of synthetic azo dye wastewater treatment using Graphene oxide nanoplatelets: Characterization toxicity evaluation and optimization using Artificial Neural Network.

    Science.gov (United States)

    Banerjee, Priya; Sau, Shubhra; Das, Papita; Mukhopadhayay, Aniruddha

    2015-09-01

    Azo dyes pose a major threat to current civilization by appearing in almost all streams of wastewater. The present investigation was carried out to examine the potential of Graphene oxide (GO) nanoplatelets as an efficient, cost-effective and non-toxic azo dye adsorbent for efficient wastewater treatment. The treatment process was optimized using Artificial Neural Network for maximum percentage dye removal and evaluated in terms of varying operational parameters, process kinetics and thermodynamics. A brief toxicity assay was also designed using fresh water snail Bellamya benghalensis to analyze the quality of the treated solution. 97.78% removal of safranin dye was obtained using GO as adsorbent. Characterization of GO nanoplatelets (using SEM, TEM, AFM and FTIR) reported the changes in its structure as well as surface morphology before and after use and explained its prospective as a good and environmentally benign adsorbent in very low quantities. The data recorded when subjected to different isotherms best fitted the Temkin isotherm. Further analysis revealed the process to be endothermic and chemisorption in nature. The verdict of the toxicity assay rendered the treated permeate as biologically safe for discharge or reuse in industrial and domestic purposes. PMID:25966335

  15. Thermal, optical and photoinduced properties of a series of homo and co-polyimides with two kinds of covalently bonded azo-dyes and their supramolecular counterparts

    Science.gov (United States)

    Konieczkowska, Jolanta; Wojtowicz, Magdalena; Sobolewska, Anna; Noga, Joanna; Jarczyk-Jedryka, Anna; Kozanecka-Szmigiel, Anna; Schab-Balcerzak, Ewa

    2015-10-01

    The paper describes the synthesis and characterization of new aromatic polyimides with one or two different moieties of the azo-dyes covalently attached to the polymer backbone and their supramolecular analogues. Azo-functionalized polyimides were prepared using post-polymerization method including the introduction of Disperse Red 13 and/or 4-[4-(6-hydroxyhexyloxy)phenylazo]pyridine to homo and co-polyimides containing hydroxyl groups via Mitsunobu reaction. The degree of functionalization of polymers with chromophores was estimated by UV-Vis spectroscopy. Polyimides containing hydroxyl groups were applied as matrixes to create supramolecular systems based on hydrogen bonds. Hydrogen-bond interactions in azosystems were studied by FTIR spectroscopy. The polymers were characterized by 1H NMR, FTIR, X-ray, UV-Vis, DSC and TGA methods. The photoisomerization process was investigated in supramolecular systems. The light-induced anisotropy was studied in a holographic gratings recording experiment and by photoinduced birefringence measurements. The polymer films were investigated by atomic force microscopy (AFM) after the diffraction grating recording to confirm formation of surface relief gratings (SRGs). To the best of our knowledge, that the first time photoinduced anisotropy has been studied by birefringence measurements in polyimides containing two different azo-dyes.

  16. Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor

    Directory of Open Access Journals (Sweden)

    Harshad Lade

    2015-06-01

    Full Text Available A microbial consortium that is able to grow in wheat bran (WB medium and decolorize the carcinogenic azo dye Congo red (CR was developed. The microbial consortium was immobilized on polyurethane foam (PUF. Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L−1 within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI removal for real textile effluent (RTE, 50% was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L−1 and 92% ADMI removal of RTE (50% at 35 and 20 mL·h−l flow rates, respectively. Consequent reduction in TOC (83 and 79%, COD (85 and 83% and BOD (79 and 78% of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents.

  17. Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor.

    Science.gov (United States)

    Lade, Harshad; Govindwar, Sanjay; Paul, Diby

    2015-06-01

    A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L-1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent (RTE, 50%) was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L-1) and 92% ADMI removal of RTE (50%) at 35 and 20 mL·h-l flow rates, respectively. Consequent reduction in TOC (83 and 79%), COD (85 and 83%) and BOD (79 and 78%) of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents. PMID:26086710

  18. Mineralization and Detoxification of the Carcinogenic Azo Dye Congo Red and Real Textile Effluent by a Polyurethane Foam Immobilized Microbial Consortium in an Upflow Column Bioreactor

    Science.gov (United States)

    Lade, Harshad; Govindwar, Sanjay; Paul, Diby

    2015-01-01

    A microbial consortium that is able to grow in wheat bran (WB) medium and decolorize the carcinogenic azo dye Congo red (CR) was developed. The microbial consortium was immobilized on polyurethane foam (PUF). Batch studies with the PUF-immobilized microbial consortium showed complete removal of CR dye (100 mg·L−1) within 12 h at pH 7.5 and temperature 30 ± 0.2 °C under microaerophilic conditions. Additionally, 92% American Dye Manufactureing Institute (ADMI) removal for real textile effluent (RTE, 50%) was also observed within 20 h under the same conditions. An upflow column reactor containing PUF-immobilized microbial consortium achieved 99% CR dye (100 mg·L−1) and 92% ADMI removal of RTE (50%) at 35 and 20 mL·h−l flow rates, respectively. Consequent reduction in TOC (83 and 79%), COD (85 and 83%) and BOD (79 and 78%) of CR dye and RTE were also observed, which suggested mineralization. The decolorization process was traced to be enzymatic as treated samples showed significant induction of oxidoreductive enzymes. The proposed biodegradation pathway of the dye revealed the formation of lower molecular weight compounds. Toxicity studies with a plant bioassay and acute tests indicated that the PUF-immobilized microbial consortium favors detoxification of the dye and textile effluents. PMID:26086710

  19. Application of Acidic Treated Pumice as an Adsorbent for the Removal of Azo Dye from Aqueous Solutions:kinetic, Equilibrium and Thermodynamic Studies

    Directory of Open Access Journals (Sweden)

    Saied Bashiri

    2012-11-01

    Full Text Available Colored effluents are one of the important environment pollution sources since they contain unused dye compounds which are toxic and less-biodegradable. In this work removal of Acid Red 14 and Acid Red 18 azo dyes was investigated by acidic treated pumice stone as anefficient adsorbent at various experimental conditions. Removal of dye increased with increase in contact time and initial dye concentration, while decreased for increment in solution temperature and pH. Results of the equilibrium study showed that the removal ofAR14 and AR18 followed Freundlich (r2>0.99 and Langmuir (r2>0.99 isotherm models.Maximum sorption capacities were 3.1 and 29.7 mg/g for AR 14 and AR18, namely significantly higher than those reported in the literature, even for activated carbon. Fitting of experimental data onto kinetic models showed the relevance of the pseudo-second order (r2>0.99 and intra-particle diffusion (r2>0.98 models for AR14 and AR18, respectively. For both dyes, the values of external mass transfer coefficient decreased for increasing initial dye concentrations, showing increasing external mass transfer resistance at solid/liquid layer.Desorption experiments confirmed the relevance of pumice stone for dye removal, since the pH regeneration method showed 86% and 89 % regeneration for AR14 and AR18,respectively.

  20. Catalytic role of Au-TiO2 nanocomposite on enhanced degradation of an azo-dye by electrochemically active biofilms: a quantized charging effect

    International Nuclear Information System (INIS)

    A green and sustainable approach to azo dye degradation by an electrochemically active biofilm (EAB) with Au-TiO2 nanocomposite assistance (average size of Au ∼8 nm) has been developed with high efficiency and mineralization of toxic intermediates. The EAB-Au-TiO2 system degraded the dye more rapidly than the EAB without the nanocomposite, which indicated the catalytic role of the Au-TiO2 nanocomposite on the dye degradation. Toxicity measurements showed that the dye wastewater treated by the EAB-Au-TiO2 system was almost non-toxic while the dye wastewater treated by the EAB without the nanocomposite showed a high toxicity compared to the parent dye. Quantized charging and Fermi level equilibration within the Au-TiO2 nanocomposite may be attributed to the excellent catalytic activity of the nanocomposite on the dye degradation. A mechanism of the catalytic activity is also proposed. Redox behavior and quantized charging of the nanocomposite were confirmed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), respectively. The proposed protocol can be effectively utilized in wastewater treatment applications.

  1. Occurrence and risk assessment of an azo dye - The case of Disperse Red 1.

    Science.gov (United States)

    Vacchi, Francine Inforçato; Von der Ohe, Peter Carsten; Albuquerque, Anjaína Fernandes de; Vendemiatti, Josiane Aparecida de Souza; Azevedo, Carina Cristina Jesus; Honório, Jaqueline Gonçalves; Silva, Bianca Ferreira da; Zanoni, Maria Valnice Boldrin; Henry, Theodore B; Nogueira, Antonio J; Umbuzeiro, Gisela de Aragão

    2016-08-01

    Water quality criteria to protect aquatic life are not available for most disperse dyes which are often used as commercial mixtures in textile coloration. In this study, the acute and chronic toxicity of the commercial dye Disperse Red 1 (DR1) to eight aquatic organisms from four trophic levels was evaluated. A safety threshold, i.e. Predicted No-Effect Concentration (PNEC), was derived based on the toxicity information of the commercial product and the purified dye. This approach was possible because the toxicity of DR1 was accounting for most of the toxicity of the commercial mixture. A long-term PNEC of 60 ng L(-1) was proposed, based on the most sensitive chronic endpoint for Daphnia similis. A short-term PNEC of 1800 ng L(-1) was proposed based on the most sensitive acute endpoint also for Daphnia similis. Both key studies have been evaluated with the new "Criteria for Reporting and Evaluating ecotoxicity Data" (CRED) methodology, applying more objective criteria to assess the quality of toxicity tests, resulting in two reliable and relevant endpoints with only minor restrictions. HPLC-MS/MS was used to quantify the occurrence of DR1 in river waters of three sites, influenced by textile industry discharges, resulting in a concentration range of 50-500 ng L(-1). The risk quotients for DR1 obtained in this work suggest that this dye can pose a potential risk to freshwater biota. To reduce uncertainty of the derived PNEC, a fish partial or full lifecycle study should be performed. PMID:27174821

  2. Biodegradation of Azo Dye RO16 in Different Reactors by Immobilized Irpex lacteus

    Czech Academy of Sciences Publication Activity Database

    Tavčar, M.; Svobodová, Kateřina; Kuplenk, J.; Novotný, Čeněk; Pavko, A.

    2006-01-01

    Roč. 53, - (2006), s. 338-343. ISSN 1318-0207 R&D Projects: GA MŠk(CZ) 1P05ME828; GA AV ČR(CZ) IAA6020411; GA ČR(CZ) GP526/06/P102 Institutional research plan: CEZ:AV0Z50200510 Keywords : irpex lacteus * dye decolorization * trickle bed reactor Subject RIV: EE - Microbiology, Virology Impact factor: 0.703, year: 2006

  3. DECOLORIZATION AND BIOLOGICAL DEGRADATION OF AZO DYE REACTIVE RED2 BY ANAEROBIC/AEROBIC SEQUENTIAL PROCESS

    OpenAIRE

    A. Naimabadi ، H. Movahedian Attar ، A. Shahsavani

    2009-01-01

    This study investigates the anaerobic treatability of reactive Red2 in an anaerobic/aerobic sequential process. Laboratory scale anaerobic baffled reactor and fixed activated sludge reactor were operated at different organic loadings and hydraulic retention times. The effects of shock dye concentration on the chemical oxygen demand and color removal efficiencies were investigated in the anaerobic baffled reactor. The effect of hydraulic retention time on the color and chemical oxygen demand r...

  4. Decolorization and detoxification of sulfonated azo dye methyl orange by Kocuria rosea MTCC 1532.

    Science.gov (United States)

    Parshetti, G K; Telke, A A; Kalyani, D C; Govindwar, S P

    2010-04-15

    Kocuria rosea (MTCC 1532) showed 100% decolorization of methyl orange (50 mg l(-1)) under static condition. The optimum pH and temperature for dye decolorization was 6.8 and 30 degrees C, respectively. The K. rosea (MTCC 1532) showed maximum decolorization of methyl orange when growth medium containing yeast extract as compared to other substrates. The culture exhibited significant ability to decolorize repeated additions of dye, with reduction in time up to 12 h at eighth dye aliquot addition. Significant induction of reductases (NADH-DCIP reductase and azoreductase) suggests its involvement in decolorization of methyl orange. The metabolites formed after decolorization of methyl orange, such as 4-amino sulfonic acid and N,N'-dimethyl p-phenyldiamine were characterized using FTIR and MS. Phytotoxicity and microbial toxicity study showed the methyl orange was toxic and metabolites obtained after its decolorization was nontoxic for experimental plants (Triticum aestivum and Phaseolus mungo) and bacteria (K. rosea, Pseudomonas aurugenosa and Azatobacter vinelandii). PMID:19969416

  5. Predictive modeling of an azo metal complex dye sorption by pumpkin husk.

    Science.gov (United States)

    Çelekli, Abuzer; Bozkurt, Hüseyin

    2013-10-01

    Effective disposal of pumpkin husk (PH) as a redundant waste is a significant work for environmental protection and full utilization of resource. Predictive modeling of sorption of Lanaset Red (LR) G on PH was investigated in a batch system as functions of particle size, adsorbent dose, pH, temperature, and initial dye concentration. Fourier transform infrared spectroscopy attenuated total reflectance spectra of PH powders before and after the sorption of LR G were determined. Sorption process was found to be dependent on particle size, adsorbent dose, pH, temperature, initial dye concentration, and contact time. Amine and amide groups of PH had significant effect on the sorption process. The pHzpc of PH was found as 6.4. Sorption process was very fast initially and reached equilibrium within 60 min. Dynamic behavior of sorption was well represented by logistic and Avrami models. The sorption of LR G on PH was excellently described by Langmuir model, indicating a homogeneous phenomenon. Monolayer sorption capacity decreased from 440.78 to 436.28 mg g(-1) with increasing temperature. Activation energy, thermodynamic, and desorption studies showed that this process was physical character, exothermic, and spontaneous. This study confirmed that PH as an effective and low-cost adsorbent had a great potential for the removal of LR G as an alternative eco-friendly process. PMID:23625123

  6. Interaction between toxic azo dye C.I. Acid Red 88 and serum albumins

    Energy Technology Data Exchange (ETDEWEB)

    Naveenraj, Selvaraj [Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India); Solomon, Rajadurai Vijay; Venuvanalingam, Ponnambalam [School of Chemistry, Bharathidasan University, Tiruchirappalli 620024 (India); Asiri, Abdullah M. [The Center of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah 21413, P.O. Box 80203 (Saudi Arabia); Anandan, Sambandam, E-mail: sanand@nitt.edu [Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India)

    2013-11-15

    Serum albumin-toxic dye interaction studies will be of paramount importance in the field of toxicology due to its relation towards the distribution and transportation of dye in blood. In this regard, the binding between C.I. Acid Red 88 (AR88) and serum albumins (HSA and BSA) was investigated by using combination of spectroscopic and molecular modeling methods. The fluorescence results revealed that AR88 interact with serum albumins through the combination of static and dynamic quenching mechanism. The distance “r” between serum albumin and AR88 was obtained according to the Forster resonance energy transfer (FRET) theory. Synchronous fluorescence and CD spectral results showed alterations in the microenvironment and conformation of serum albumins. The molecular docking method is also employed to understand the interaction of AR88 with serum albumins. All these studies confirm that BSA has more affinity towards AR88 than that of HSA which suggests that AR88 is more easily transported in the body of bovid than human and so it is more hazardous to bovids. -- Highlights: • AR88 interacts with serum albumin through the combination of both static and dynamic quenching mechanism. • The binding site of AR88 in serum albumins is nearer to tryptophan moiety. • Circular Dichroism spectra showed that AR88 alters α-helicity of serum albumin. • This interaction study could be greatly imperative for further investigations in toxicology.

  7. DECOLORIZATION AND BIOLOGICAL DEGRADATION OF AZO DYE REACTIVE RED2 BY ANAEROBIC/AEROBIC SEQUENTIAL PROCESS

    Directory of Open Access Journals (Sweden)

    A. Naimabadi ، H. Movahedian Attar ، A. Shahsavani

    2009-04-01

    Full Text Available This study investigates the anaerobic treatability of reactive Red2 in an anaerobic/aerobic sequential process. Laboratory scale anaerobic baffled reactor and fixed activated sludge reactor were operated at different organic loadings and hydraulic retention times. The effects of shock dye concentration on the chemical oxygen demand and color removal efficiencies were investigated in the anaerobic baffled reactor. The effect of hydraulic retention time on the color and chemical oxygen demand removal efficiencies were also investigated in the aerobic reactor. The studies were carried out in continuous mode and the effluent of the anaerobic baffled reactor was used as feed for the fixed activated sludge reactor. Chemical oxygen demand removal efficiency of 54.5% was obtained at HRT =1 day in the anaerobic reactor. The average color removal was 89.5%. Chemical oxygen demand removal efficiency of 69% was obtained at HRT =7 h in the aerobic fixed activated sludge reactor. A slight decrease of the color was also observed in the aerobic reactor. This investigation has shown that successful treatment of a highly colored wastewater is possible in the anaerobic baffled reactor. Also the results showed that, anaerobic biological system has higher efficiency in dye removal than fixed activated sludge system, while aerobic system has higher efficiency in chemical oxygen demand removal comparing with the anaerobic baffled reactor.

  8. Iron promotion of the TiO2 photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation

    International Nuclear Information System (INIS)

    Highlights: → Azo dye photooxidation occurs under strict combination of ultraviolet and visible irradiation of Fe-TiO2. → Fe3+ enhances the TiO2 photooxidation of azo dyes while decreases that of phenol. → UV irradiation leads to a decrease in photooxidation activity of Fe-TiO2 photocatalysts. - Abstract: The photocatalytic oxidation of the azo dye Orange-II (Or-II) using Fe loaded TiO2 (Fe-TiO2) was studied under ultraviolet (UV), visible (vis) and simultaneous UV-vis irradiations using a solar light simulator. Photocatalysts were characterized by means of XRD, SEM-EDX, FTIR and DRS. Fe3+ species, identified in XPS analyses, were responsible of the increased absorption of visible light. Moreover, DRS analyses showed a decrease in the bandgap due to Fe3+ loading. Photocatalystic tests proved that Fe modification enhanced the TiO2 photocatalytic activity towards Or-II photodegradation under simultaneous UV-vis irradiation. Even so, the performance of the Fe-TiO2 samples towards the photodegradation of phenol, under UV irradiation, was lower than TiO2 suggesting the recombination of the UV photogenerated electron-hole pair. Therefore, results evidence a Fe3+ promotion of the electron caption in the photosensitization process of TiO2 by Or-II acting as a sensitizer. Such process leads to the Or-II photooxidation under UV-vis irradiation by losing energy in electron transferring processes to sensitize TiO2, and, the formation of reactive oxygen species promoted by the injected electron to the TiO2 conduction band.

  9. Iron promotion of the TiO{sub 2} photosensitization process towards the photocatalytic oxidation of azo dyes under solar-simulated light irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Camilo A.; Centeno, Aristobulo [Centro de Investigaciones en Catalisis (CICAT), Escuela de Ingenieria Quimica, Universidad Industrial de Santander (UIS), A.A. 678, Bucaramanga (Colombia); Giraldo, Sonia A., E-mail: sgiraldo@uis.edu.co [Centro de Investigaciones en Catalisis (CICAT), Escuela de Ingenieria Quimica, Universidad Industrial de Santander (UIS), A.A. 678, Bucaramanga (Colombia)

    2011-10-03

    Highlights: {yields} Azo dye photooxidation occurs under strict combination of ultraviolet and visible irradiation of Fe-TiO{sub 2}. {yields} Fe{sup 3+} enhances the TiO{sub 2} photooxidation of azo dyes while decreases that of phenol. {yields} UV irradiation leads to a decrease in photooxidation activity of Fe-TiO{sub 2} photocatalysts. - Abstract: The photocatalytic oxidation of the azo dye Orange-II (Or-II) using Fe loaded TiO{sub 2} (Fe-TiO{sub 2}) was studied under ultraviolet (UV), visible (vis) and simultaneous UV-vis irradiations using a solar light simulator. Photocatalysts were characterized by means of XRD, SEM-EDX, FTIR and DRS. Fe{sup 3+} species, identified in XPS analyses, were responsible of the increased absorption of visible light. Moreover, DRS analyses showed a decrease in the bandgap due to Fe{sup 3+} loading. Photocatalystic tests proved that Fe modification enhanced the TiO{sub 2} photocatalytic activity towards Or-II photodegradation under simultaneous UV-vis irradiation. Even so, the performance of the Fe-TiO{sub 2} samples towards the photodegradation of phenol, under UV irradiation, was lower than TiO{sub 2} suggesting the recombination of the UV photogenerated electron-hole pair. Therefore, results evidence a Fe{sup 3+} promotion of the electron caption in the photosensitization process of TiO{sub 2} by Or-II acting as a sensitizer. Such process leads to the Or-II photooxidation under UV-vis irradiation by losing energy in electron transferring processes to sensitize TiO{sub 2}, and, the formation of reactive oxygen species promoted by the injected electron to the TiO{sub 2} conduction band.

  10. 负载型纳米Fe-Pd降解水溶性偶氮染料%Degradation of azo dye by resin-supported nano-iron/palladium

    Institute of Scientific and Technical Information of China (English)

    武俐; 邰超; 王晴晴; 赵同谦

    2012-01-01

    采用阳离子交换树脂表面为载体,合成了负载型纳米Fe-Pd二元复合金属材料,采用扫描电子显微镜(SEM)和能谱分析对该材料进行表征,研究了其对一些水溶性偶氮染料的降解效果.实验表明,该材料对0.05 g.L^-1甲基橙、日落黄、酸性橙8、金橙G和活性红2等偶氮染料有较好的降解效果,纳米双金属中Pd含量的增加有利于染料的降解;反应体系初始pH值对染料的降解率影响较大,本研究中,pH 4酸性条件下降解效果最佳;制备的材料在第10次活化后,仍有较好的降解效果;为环境中偶氮染料的降解提供了一种有效的方法.%In the paper,the resin-supported nano-iron/ palladium was synthesized by liquid-phase chemical reduction method.The obtained nano particles were characterized by scanning electron microscope(SEM),and the degradation of typical water-soluble azo dyes by the resin-supported nano-iron/palladium was studied.The experimental results indicated 0.05 g · L^-1 of typical azo dyes,including Methyl Orange,Sunset Yellow,Acid Orange 8,Orange G and Reactive Red 2,were efficiently degraded by the nano-iron/palladium.With increasing palladium content,better degradation effect of azo dyes was obtained.Initial pH was proven to have significant effect on the degradation of azo dyes,with the best degradation effect obtained in the acidic condition.The supported nano-iron/palladium still had good degradation effect even after ten cycles of degradation and activation.

  11. Descoloração redutiva de corantes azo e o efeito de mediadores redox na presença do aceptor de elétrons sulfato Reductive decolourisation of azo dyes and the effect of redox mediators in the presence of the electron acceptor sulfate

    Directory of Open Access Journals (Sweden)

    Mayara Carantino Costa

    2010-01-01

    Full Text Available We investigated the impact of sulphate and the redox mediator Anthraquinone-2,6-disulfonate (AQDS on the decolorization of the azo dyes Congo Red (CR and Reactive Black 5 (RB5. In anaerobic reactors free of extra sulphate dosage, the color removal efficiency decreased drastically when the external electron donor ethanol was removed. In presence of an extra dosage of sulphate, CR decolourisations were 47.8% (free of AQDS and 96.5% (supplemented with AQDS. The decolourisations achieved in both reactors with RB5 were lower than the ones found with CR. Finally, the biogenic sulphide contribution on azo dye reduction was negligiable.

  12. Adsorption of Reactive Red 198 Azo Dye fromAqueous Solution onto theWaste Coagulation Sludge of theWater Treatment Plants

    Directory of Open Access Journals (Sweden)

    M. Mahmoudi

    2010-04-01

    Full Text Available "n "n "nBackgrounds and Objectives:Much attention has been recently paid on using waste materials as adsorbents for removal of contaminants from water and wastewater. A new low cost waste was examined for its capacity to adsorb RR198, an azo reactive model dye, from an aqueous solution."nMaterials andMethods: The waste was dried, powdered and characterized before being used as an adsorbent. The effects of pH (3-10, adsorbent dose (0.2-3 g, dye concentration and contact time on the adsorption efficiency were investigated. Equilibrium study data were modeled using Langmuir and Freundlich models."nResults: The characterization analysis indicated that itwas composedmainly of ferric hydroxide. The powder had a BET and average pore size of 107 m2/g and 4.5 nm, respectively. The results showed that dye removal was highest at a solution pH of 7 to 8 and a powder dose of 2 g/L. The RR198 removal percentage decreased from 100& to 43& at 140 min contact time when the concentration of dye was increased from 25 mg/L to 100 mg/L, at optimum pH and dosage. The Langmuir equation provided the best fit for the experimental data. The maximum adsorption capacity was calculated to be 34.4 mg/g."nConclusion: According to the obtained results, the water coagulation waste sludge appears to be a suitable low cost and effcient adsorbent for removing reactive azo dyes from waste streams.

  13. Adsorption of an azo dye in an aqueous solution using hydroxyl-terminated polybutadiene (HTPB).

    Science.gov (United States)

    Olya, Mohammad Ebrahim; Pirkarami, Azam; Mirzaie, Mohammad

    2013-05-01

    This paper reports an investigation into the effect of a number of operating factors on the removal of Acid Blue 92 (AB92) from an aqueous solution using hydroxyl-terminated polybutadiene (HTPB) as an adsorbent. The optimum values of adsorbent dose and pH were found to be 35mgL(-1) and 6, respectively. Temperature showed a significant effect, with maximum dye removal being observed at 45°C. Stirring the solution during the treatment process resulted in significant removal improvement. The Langmuir adsorption model was used to quantify the amount of AB92 adsorbed on the surface of HTPB. FT-IR spectrometry results for HTPB, AB92, and HTPB-AB92 verified the efficiency of the treatment. Further, the adsorbent was characterized using SEM and H NMR techniques. PMID:23484459

  14. Fenton oxidative decolorization of the azo dye Direct Blue 15 in aqueous solution

    DEFF Research Database (Denmark)

    Sun, Jian-Hui; Shi, Shao-Hui; Lee, Yi-Fan;

    2009-01-01

    kinetic of the DB15 were studied, the operating parameters were preferred by changing one factor at one time while the other parameters were kept constant. The optimal conditions for the decolorization of DB15 were determined as pH=4.0, [H2O2] = 2.8x10(-3) mol/L, H2O2/Fe2+ ratio = 100: 1, H2O2/dye ratio...... the reaction temperature from 20 to 40 degrees C showed a positive effect on the decolorization efficiency of DB15. The present study can provide guidance to relational industry operators and planners to effectively treat the DB15 contaminated wastewater by Fenton oxidation process. (C) 2009 Elsevier...

  15. Highly efficient visible light mediated azo dye degradation through barium titanate decorated reduced graphene oxide sheets

    Science.gov (United States)

    Rastogi, Monisha; Kushwaha, H. S.; Vaish, Rahul

    2016-03-01

    This study investigates BaTiO3 decorated reduced graphene oxide sheets as a potential visible light active catalyst for dye degradation (Rhodamine B). The composites were prepared through conventional hydrothermal synthesis technique using hydrazine as a reducing agent. A number of techniques have been employed to affirm the morphology, composition and photocatalytic properties of the composites; these include UV-visible spectrophotoscopy that assisted in quantifying the concentration difference of Rhodamine B. The phase homogeneity of the composites was examined through x-ray powder diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) was employed to confirm the orientation of the BaTiO3 particles over the reduced graphene oxide sheets. Photoluminescence (PL) emission spectra assisted in determining the surface structure and excited state of the catalyst. Fourier transformed-infrared (FTIR) spectra investigated the vibrations and adsorption peak of the composites, thereby ascertaining the formation of reduced graphene oxide. In addition, diffuse reflectance spectroscopy (DRS) demonstrated an enhanced absorption in the visible region. The experimental investigations revealed that graphene oxide acted as charge collector and simultaneously facilitated surface adsorption and photo-sensitization. It could be deduced that BaTiO3-reduced graphene oxide composites are of significant interest the field of water purification through solar photocatalysis. [Figure not available: see fulltext.

  16. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    Energy Technology Data Exchange (ETDEWEB)

    Vallet, Ana, E-mail: avallet@quim.ucm.es [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain); Besson, Michele, E-mail: michele.besson@ircelyon.univ-lyon1.fr [IRCELYON, Institut de recherches sur la catalyse et l' environnement de Lyon, UMR5256 CNRS-Universite Lyon1, 2 Avenue Albert Einstein, F-69626 Villeurbanne Cedex (France); Ovejero, Gabriel; Garcia, Juan [Grupo de Catalisis y Procesos de Separacion (CyPS), Departamento de Ingenieria Quimica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040 Madrid (Spain)

    2012-08-15

    Highlights: Black-Right-Pointing-Pointer Ni supported over hydrotalcite calcined precursors as catalyst. Black-Right-Pointing-Pointer Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. Black-Right-Pointing-Pointer Dye removal depends on temperature, initial dye concentration and flow rate. Black-Right-Pointing-Pointer The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 Degree-Sign C. An increase in the reaction temperature (120-180 Degree-Sign C), and a decrease in dye concentration (1000-3000 ppm) or liquid flow rate (0.1-0.7 mL min{sup -1}) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min{sup -1} and 180 Degree-Sign C under 5 MPa air.

  17. Treatment of a non-azo dye aqueous solution by CWAO in continuous reactor using a Ni catalyst derived from hydrotalcite-like precursor

    International Nuclear Information System (INIS)

    Highlights: ► Ni supported over hydrotalcite calcined precursors as catalyst. ► Catalytic wet air oxidation in trickle bed reactor for Basic Yellow 11 removal. ► Dye removal depends on temperature, initial dye concentration and flow rate. ► The catalyst proved to be stable and efficient for the dye degradation. - Abstract: Catalytic wet air oxidation (CWAO) of a Basic Yellow 11 (BY11) aqueous solution, chosen as a model of a hardly biodegradable non-azo dye was carried out in a continuous-flow trickle-bed reactor, using nickel supported over hydrotalcite precursor calcined at 550 °C. An increase in the reaction temperature (120–180 °C), and a decrease in dye concentration (1000–3000 ppm) or liquid flow rate (0.1–0.7 mL min−1) enhanced the CWAO performance in a 30 and 19% for the variation of the temperature and concentration respectively. After a small leaching observed within the first hours, the catalyst proved to be very stable during the 65-day reaction. The CWAO process was found to be very efficient, achieving BY11 conversion up to 95% and TOC conversion up to 85% at 0.1 mL min−1 and 180 °C under 5 MPa air.

  18. A comparative investigation on adsorption performances of mesoporous activated carbon prepared from waste rubber tire and activated carbon for a hazardous azo dye-Acid Blue 113

    International Nuclear Information System (INIS)

    Research highlights: → The system is cheap, efficient and fast for the removal of dyes from waters. → Higher adsorption capacity is due to higher mesoporous volume of the adsorbent. → The rate determining step of the adsorption process is particle diffusion. - Abstract: A mesoporous carbon developed from waste tire rubber, characterized by chemical analysis, FTIR, and SEM studies, was used as an adsorbent for the removal and recovery of a hazardous azo dye, Acid Blue 113. Surface area, porosity, and density were determined. The adsorption of the dye over the prepared adsorbent and a commercial activated carbon was achieved under different pH, adsorbate concentration, sieve size, adsorbent dosage, contact time and temperature conditions. Langmuir and Freundlich adsorption isotherm models were applied and thermodynamic parameters were calculated. Kinetic studies indicated that the adsorption process follow first order kinetics and particle diffusion mechanisms are operative. By percolating the dye solution through fixed-bed columns the bulk removal of the Acid Blue 113 was carried out and necessary parameters were determined to find out the percentage saturation of both the columns. Recovery of the dye was made by eluting 0.1 M NaOH through the column.

  19. Comparison of two bacterial azoreductases acquired during adaptation to growth on azo dyes.

    Science.gov (United States)

    Zimmermann, T; Gasser, F; Kulla, H G; Leisinger, T

    1984-05-01

    Selection for utilization of carboxy-Orange I [1-(4'-carboxyphenylazo)-4-naphthol] in the chemostat yielded Pseudomonas strain K24 which was unable to grow on carboxy-Orange II [1-(4'-carboxyphenylazo)-2-naphthol] while selection for growth on carboxy-Orange II had previously led to strain KF46 which did not utilize carboxy-Orange I. Orange I azoreductase of strain K24, the key enzyme of dye degradation, was purified 80-fold with 17% yield to electrophoretic homogeneity and compared to the previously purified Orange II azoreductase of strain KF46. Common properties of the two enzymes were their monomeric structure, their specificity for NADPH and NADH as cosubstrates, the range of their Km values for substrates and cosubstrates as well as their reactivity towards a series of substrate analogs. They differed from each other with respect to molecular weight (21,000 and 30,000) and in the absolute requirement of Orange I azoreductase for a hydroxy group in the 4'position of the naphthol ring of the substrate molecule as compared to the requirement for substrates with a 2-naphthol moiety by Orange II azoreductase. The pure enzymes did not exhibit immunological cross-reaction with each other. Crude extracts of strains K24 and KF46 and of azoreductase-negative strains isolated at different stages of the adaptation experiments, however, contained material which cross-reacted (CRM) with both anti Orange I azoreductase serum and anti Orange II azoreductase serum. The CRM may represent a common precursor protein of the azoreductases in strains K24 and KF46. PMID:6742955

  20. New copolymer of acrylamide with allyl methacrylate and its capacity for the removal of azo dyes

    Directory of Open Access Journals (Sweden)

    Yeliz Yildirim

    2015-04-01

    Full Text Available The copolymerization reactions of Acrylamide (AA with the different mole ratios of allyl methacrylate (AMA such as 25/75, 50/50 and 75/25 were studied by radical polymerization under argon atmosphere using 2,2’-Azobis (isobutyronitri1e (AIBN as initiator. The copolymers were characterized with Fourier transform infrared spectroscopy (FTIR and thermogravimetric analysis (TG. FTIR spectra showed that the C=O, C-N and N-H groups in copolymers remained during the copolymerization. It is concluded from the thermograms that Poly(AA-co-AMA copolymers which contained different ratios of monomer and comonomer exhibit similar thermal behavior. Adsorption capacity, kinetic and isotherm studies of Direct Brown 2 onto the copolymers have been evaluated. Different factors such as the monomer ratio, pH, initial dye concentration, copolymer dosage and contact time affecting the removal process were studied. It was found that the adsorption process agreed with the Freundlich and Dubinin-Raduskevich model and the adsorption of Direct Brown 2 depended on the acrylamide content and pH of the solution. The standard Gibb’s free energy was determined as - 14.7 kJ/mol, which means that adsorption occurred spontaneously and the process is feasible. Increasing the acrylamide content led to increased adsorption of Direct Brown 2 on the copolymer. Moreover, adsorption kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model, indicating that the chemical adsorption was the rate-limiting step. These results show that Poly(AA-co-AMA can be used as adsorbent for water pollutants such as Direct Brown 2 and has potential applications in related industrial and environmental areas.

  1. Electrochemical characteriztion of the bioanode during simultaneous azo dye decolorization and bioelectricity generation in an air-cathode single chambered microbial fuel cell

    International Nuclear Information System (INIS)

    To achieve high power output based on simultaneously azo dye decolorization using microbial fuel cell (MFC), the bioanode responses during decolorization of a representative azo dye, Congo red, were investigated in an air-cathode single chambered MFC using representative electrochemical techniques. It has been found that the maximum stable voltage output was delayed due to slowly developed anode potential during Congo red decolorization, indicating that the electrons recovered from co-substrate are preferentially transferred to Congo red rather than the bioanode of the MFC and Congo red decolorization is prior to electricity generation. Addition of Congo red had a negligible effect on the Ohmic resistance (Rohm) of the bioanode, but the charge-transfer resistance (Rc) and the diffusion resistance (Rd) were significantly influenced. The Rc and Rd firstly decreased then increased with increase of Congo red concentration, probably due to the fact that the Congo red and its decolorization products can act as electron shuttle for conveniently electrons transfer from bacteria to the anode at low concentration, but result in accelerated consumption of electrons at high concentration. Cyclic voltammetry results suggested that Congo red was a more favorable electron acceptor than the bioanode of the MFC. Congo red decolorization did not result in a noticeable decrease in peak catalytic current until Congo red concentration up to 900 mg l-1. Long-term decolorization of Congo red resulted in change in catalytic active site of anode biofilm.

  2. Microextraction by packed sorbent and salting-out-assisted liquid-liquid extraction for the determination of aromatic amines formed from azo dyes in textiles.

    Science.gov (United States)

    Sánchez, Miguel del Nogal; Santos, Patricia Martín; Sappó, Cristina Pérez; Pavón, José Luis Pérez; Cordero, Bernardo Moreno

    2014-02-01

    EU legislation prohibits the use of certain azo dyes which, on reduction, form any of 22 aromatic amines listed in Regulation (EC) 1907/2006 at concentrations above the threshold limit of 30 mg Kg(-1). Two different extraction techniques for the determination of aromatic amines formed from azo dyes in textiles in combination with gas chromatography-mass spectrometry (GC-MS) are described. The first one is based on microextraction by packed sorbent (MEPS) and the other approach involves salting-out-assisted liquid-liquid extraction (SALLE). The influence of several parameters on the efficiency of the extraction using MEPS (sorbent material, sample volume, elution solvent, elution volume and washing steps, among others) and SALLE (extraction volume and amount of salt) were investigated. In addition, chromatographic separation was optimized and quadrupole mass spectrometry was evaluated using the synchronous SIM/scan data acquisition mode. The repeatability (n=8, S/N=3) of the methods, calculated as the relative standard deviation (RSD) was below 15 and 11% for all compounds when MEPS and SALLE were used, respectively. Standard additions procedure was used to quantify the aromatic amines in the textil samples. The detection limits in the samples for both methods were lower than the maximum value allowed by legislation. The results obtained in the analysis of textiles revealed the presence of o-anisidine, p-chloroaniline, 4-chloro-o-toluidine, 2-naphthylamine and 3,3'-dimethoxybenzidine in some of them. PMID:24401428

  3. Evaluation of the treatment performance of lab-scaled vertical flow constructed wetlands in removal of organic compounds, color and nutrients in azo dye-containing wastewater.

    Science.gov (United States)

    Dogdu, Gamze; Yalcuk, Arda

    2016-01-01

    The objective of this study is to examine the treatment performance of vertical flow intermittent feeding constructed wetland (VFCW) in removal of organic pollution, nutrients and color in azo-dye containing wastewater. The systems consisted of PVC reactors, some filling materials such as gravel, sand and zeolite and wetland plants including Typha angustifolia and Canna indica. The average treatment efficiency of the systems for COD, color, sulphate, NH4-N, and PO4-P were in the range of 57-63%, 94-99%, 44-48%, 39-44%, and 84-88%, respectively among the VFCW reactors. It is concluded that VFCW reactor system can effectively be used in the treatment of dye-rich wastewater, especially for the removal of color and in the reduction of COD. Biofilm formation and cleavage of azo bonds could be observed by SEM and FTIR results, respectively. Almost similar NH4-N and PO4-P removal were obtained in all reactors by using same amount of zeolite media. PMID:26248021

  4. Removal of anionic azo dye from aqueous solution via an adsorption-photosensitized regeneration process on a TiO2 surface.

    Science.gov (United States)

    Bao, Nan; Li, Yuan; Yu, Xiao-Hong; Niu, Jun-Jian; Wu, Guo-Lin; Xu, Xiao-Hong

    2013-02-01

    Textile dye effluents are typically characterized by strong color and recalcitrance, even at very low concentration. The process of enrichment of anionic azo dye on the surface of TiO(2) fibers followed by photosensitization degradation under ambient air conditions was extensively investigated. Adsorption isotherms and zeta potentials were used to describe the "dye/TiO(2) surface" interface, taking into account the effects of pH on the nature and population of the surface groups on the TiO(2) fibers. The extent of the photocatalytic degradation of dye on TiO(2) surface was determined by FTIR. N(2) adsorption isotherms and optical spectra were employed to investigate the effect of photosensitization. The adsorption of dyes on the TiO(2) surface occurs via electrostatic attraction through the formation of single- or multidentate-coordinated surface complexes. Almost complete photobleaching of the absorption band at 534 nm is achieved in ~4 h. Dye-sensitized TiO(2) fiber could absorb part of the visible light spectrum (λ < 600 nm). Interfacial electron transfer can potentially alter the degradation efficiency. The regenerated TiO(2) fiber could be reused for subsequent decolorization without a decline in adsorption efficiency compared with freshly prepared TiO(2) samples, which may be attributed to preservation of the hierarchical pore structure and restoration of the original surface properties. In summary, we propose an efficient "adsorption-photoregeneration-reuse" process applying TiO(2) fibers for the degradation of dyes in water. PMID:22544602

  5. The UV and Laser Aging for PMMA/BDK/Azo-dye Polymer Blend Cured by UV Light Beams

    Science.gov (United States)

    Ahmad, A. A.; Omari, A. M.

    2015-10-01

    A polymeric-based solution blend composed of Azo-dye methyl red (MR) doped with polymethelmethacrelate (PMMA) solution, in addition, to the BenzylDimethylKetal (BDK) photoinitiator was made with optimum molar ratios and deposited on glass substrate by spin coating technique. The samples were then exposed to UV light beams in order to assist the layers polymerization by the proper exposure process. The photo chemical reaction occurred during the UV light polymerization process induces photo refractive changes which were presented as a function of wavelength or photon energy. Two main strong absorption peaks were observed in the films at around 330 nm (3.75 eV) and 500 nm (2.48 eV) for different curing time periods. This phenomenon enhances the films usage for optical data storage media at these two wavelengths. Since the deposited films were then useful as based layers for Read/Write optical data storage media, they were then tested by UV or laser Read/Write beams independently. The optical properties of the films were investigated while exposed to each beam. Finally, their optical properties were investigated as a function of aging time in order to relate the temporary and/or permanent light-exposure effect on the films compared to their optical properties before the light exposure. The films show a low absorbance at 630 nm (1.97 eV) and high absorbance at 480 nm (2.58 eV). This fact makes it possible to record holographic gratings in the polymeric film upon light exposure. In all cases the optical properties were evaluated by using the very sensitive, non destructive surface testing spectroscopic ellipsometry technique. The films were characterized in the spectral range of 300 to 1000 nm using Lorentz oscillator model with one oscillator centred at 4.15 eV. This study has been supported by the SEM and EDAX results to investigate the effect of the UV and visible beams on their optical properties. The results of this research determined the proper conditions for

  6. Characterization of pore-expanded amino-functionalized mesoporous silicas directly synthesized with dimethyldecylamine and its application for decolorization of sulphonated azo dyes

    International Nuclear Information System (INIS)

    With dimethyldecylamine (DMDA) as the expander, a new kind of pore-expanded amino-functionalized mesoporous silicas (PEAFMS) was directly synthesized under mild alkali condition. The characteristics of PEAFMS sample demonstrated that the presence of DMDA markedly augmented the average pore diameter (19.04 nm) and strongly enhanced its decolorization ability. Subsequently, acid mordant dark yellow GG (YGG) and reactive red violet X-2R (RVX) were chosen to assess its adsorption capacity for sulphonated azo dyes. The effect of initial pH was investigated and the decolorization mechanism was illuminated. Three isotherms were conducted and the goodness of fit increased as the following order: Freundlich < Langmuir < Redlich-Peterson. The maximum adsorption capacities of YGG and RVX onto PEAFMS were 1.967 and 0.957 mmol/g, respectively. Adsorption kinetic processes were better predicted by the pseudo-second-order rate equation than the pseudo-first-order one. Adsorption thermodynamic results suggested that the adsorption behavior of both dyes onto PEAFMS was spontaneous with the chemical nature. In addition, the regeneration of PEAFMS was proved to be feasible using NaOH as the strippant. After five cycles, PEAFMS still possessed a favorable adsorption capacity for dyes. It is safely concluded that PEAFMS could be a potential adsorbent for the dye removal from wastewater.

  7. Colorful and transparent poly(vinyl alcohol) composite films filled with layered zinc hydroxide salts, intercalated with anionic orange azo dyes (methyl orange and orange II)

    International Nuclear Information System (INIS)

    Highlights: ► Zinc hydroxide salts were successfully intercalated with anionic orange azo dyes. ► The anionic dye was co-intercalated with hydrated chloride anions. ► The orange materials were used as fillers for poly(vinyl alcohol). ► Transparent, homogeneous, colorful PVA films were obtained by wet casting. ► Some composites stored at lower humidity exhibited improved mechanical properties. - Abstract: Layered zinc hydroxide salts (zinc LHS) were intercalated with anionic orange azo dyes, namely methyl orange (MO) and orange II (OII), and co-intercalated with hydrated chloride anions. After characterization by X-ray diffraction (XRD), thermal analysis (TGA/DTA), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS), the materials were used as fillers for poly(vinyl alcohol) (PVA). Colorful transparent films were obtained by wet casting, revealing good dispersion of the material into the polymer. In the case of zinc LHS/OII, PVA was intercalated between the zinc LHS layers. Evaluation of the mechanical properties of the PVA composite films revealed that the layered colorful materials were able to increase the mechanical properties of the PVA films only when the films were stored under lower relative humidity. As expected, films with higher water content displayed reduced tensile strength and modulus because of the plasticizing effect of water. As for the films stored at 43% relative humidity, more pronounced improvement of modulus was observed for 1 and 4% zinc LHS/OII, and enhanced tensile strength was achieved for 0.5 and 1% zinc LHS/OII. This effect can be attributed to better dispersion of the layered filler and its better adhesion to the PVA matrix.

  8. Removal of Azo Dyes (Violet B and Violet 5R from Aqueous Solution Using New Activated Carbon Developed from Orange Peel

    Directory of Open Access Journals (Sweden)

    Saeedeh Hashemian

    2013-01-01

    Full Text Available Activated carbon developed from agricultural waste orange peel (COP was prepared. COP was characterized using Fourier infrared spectroscopy (FTIR, X-ray powder diffraction (XRD, scanning electron microscopy (SEM, and BET. COP has surface area and mean pore diameter of 225.6 m2 g−1 and 22.40 nm, respectively. The removal of violet B (VB and violet 5R (V5R from aqueous solutions by COP was investigated. The effect of operational parameters such as contact time, pH, initial dye concentration, and adsorbent dosage on the adsorption of dyes was investigated. Maximum dye was removed within 30 min of contact time at pH > 7. Two common models, the Langmuir and Freundlich isotherms, were used to investigate the interaction of dye and COPs. The isotherm evaluations revealed that the Langmuir model provides better fit to the experimental data than the Freundlich model. The adsorption of VB and V5R onto COP was followed by pseudo-second-order kinetic model with a good correlation (R2>0.99. Activation energies 5.47 and 29.7 KJ mol−1 were determined for violet B and violet 5R, respectively. The rate of adsorption of violet 5R was faster than that of violet B (kV5R>kVB. The prepared COP could thus be used as promising adsorbent for removal of organic dyes, especially azo dye, from polluted water. The solid COP could be conveniently regenerated after adsorption.

  9. Photo-reductive decolorization of an azo dye by natural sphalerite: Case study of a new type of visible light-sensitized photocatalyst

    International Nuclear Information System (INIS)

    Natural sphalerite, which represents a new class of mineral-based catalyst, was characterized and investigated for photo-reduction of an azo dye methyl orange (MO) under visible light. After 2 h of visible light irradiation, a complete decolorization of the MO solution was achieved. The degradation rate was related to the pH conditions. Spectra from FT-IR analysis indicate an initial adsorption of MO to sphalerite via its sulfonate group. Further reduction of the adsorbed MO by sphalerite under light irradiation led to the destruction of the azo structure, as indicated by the results from UV-vis, FT-IR and ESI-MS analyses. The visible light-induced photocatalytic reductive activity of natural sphalerite was mainly attributed to the distribution of foreign metal atoms in its crystal lattice, which reduces the intrinsic bandgap of sphalerite and also broadens its spectra responding range. In addition, the high conduction band potential of natural sphalerite may also enhance the photo-reduction of MO.

  10. Photo-reductive decolorization of an azo dye by natural sphalerite: Case study of a new type of visible light-sensitized photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Li Yan [Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Yiheyuan Road 5, Haidian District, Beijing 100871 (China); Lu Anhuai, E-mail: ahlu@pku.edu.cn [Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Yiheyuan Road 5, Haidian District, Beijing 100871 (China); Jin Song [Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY 82071 (United States); MWH Americas, 3665 JFK Parkway, Suite 206, Fort Collins, CO 80525 (United States); Wang Changqiu [Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Yiheyuan Road 5, Haidian District, Beijing 100871 (China)

    2009-10-15

    Natural sphalerite, which represents a new class of mineral-based catalyst, was characterized and investigated for photo-reduction of an azo dye methyl orange (MO) under visible light. After 2 h of visible light irradiation, a complete decolorization of the MO solution was achieved. The degradation rate was related to the pH conditions. Spectra from FT-IR analysis indicate an initial adsorption of MO to sphalerite via its sulfonate group. Further reduction of the adsorbed MO by sphalerite under light irradiation led to the destruction of the azo structure, as indicated by the results from UV-vis, FT-IR and ESI-MS analyses. The visible light-induced photocatalytic reductive activity of natural sphalerite was mainly attributed to the distribution of foreign metal atoms in its crystal lattice, which reduces the intrinsic bandgap of sphalerite and also broadens its spectra responding range. In addition, the high conduction band potential of natural sphalerite may also enhance the photo-reduction of MO.

  11. Preparation and Photovoltaic Properties of Dye Sensitized Solar Cells Using ZnO Nanorods Stacking Films on AZO Substrate as Photoanode.

    Science.gov (United States)

    Xu, Yang; Wang, Xina; Liu, Rong; Wang, Hao

    2016-04-01

    Three-dimensional stacking of ZnO nanorods on conducting aluminum-doped ZnO (AZO) glass were studied as efficient photoanodes of dye sensitized solar cells (DSSCs). By changing hydrothermal growth time and cycle times, the thickness of ZnO nanorods stacking films varied from 30 µm to 64 µm, and its influence on the energetic conversion efficiency of the DSSCs based on the stacking films photoanodes was investigated. The loading density of N719 on the surface of ZnO nanorods was studied to increase the efficiency of the cells. Annealing experiments showed that the AZO substrates remained good conductors until heated above 350 °C. A photoelectric conversion efficiency as high as ~2.0% together with ISC of ~9.5 mA/cm2, VOC of ~0.5 V and FF of ~41.4% was achieved for the DSSC using 50 µm-thick film stacking by ZnO nanorods as photoanode and N719 as sensitizer under illumination of AM1.5G solar light (power density of 100 mW/cm2). A charge separation and transfer mechanism was proposed for the ZnO nanorods stacking electrode-based DSSCs. PMID:27451677

  12. Effect of trace metals and electron shuttle on simultaneous reduction of reactive black-5 azo dye and hexavalent chromium in liquid medium by Pseudomonas sp.

    Science.gov (United States)

    Mahmood, Shahid; Khalid, Azeem; Arshad, Muhammad; Ahmad, Riaz

    2015-11-01

    This study demonstrates the role of electron shuttles and trace metals in the biotransformation of azo dye reactive black-5 and hexavalent chromium (CrVI) that are released simultaneously in tannery effluent. Previously isolated bacterial strain Pseudomonas putida KI was used for the simultaneous reduction of the dye (100 mg L(-1)) and CrVI (2 mg L(-1)) in a mineral salts medium (MSM). Among various trace metals, only Cu(II) had a stimulating effect on the bacterial-mediated reduction process. Application of electron shuttles such as hydroquinone and uric acid at a low concentration (1mM) had a positive effect on the reduction process and caused simultaneous reduction of 100% dye and 97% CrVI in 12-18 h. Mannitol, EDTA and sodium benzoate at all concentrations (ranging from 1 to 9 mM) showed an inhibitory effect on the reduction of reactive black-5 and CrVI. An inverse linear relationship between the velocity of reaction (V) and the concentration [S] of electron shuttles was observed. The results imply that both types and concentration of an electron shuttle and trace metals can affect the simultaneous reduction of reactive black-5 and CrVI. PMID:25556007

  13. Degradation of Amaranth azo dye in water by heterogeneous photo-Fenton process using FeWO4 catalyst prepared by microwave irradiation.

    Science.gov (United States)

    da Cruz Severo, Eric; Anchieta, Chayene Gonçalves; Foletto, Vitória Segabinazzi; Kuhn, Raquel Cristine; Collazzo, Gabriela Carvalho; Mazutti, Marcio Antonio; Foletto, Edson Luiz

    2016-01-01

    FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 2(3) central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process. PMID:26744938

  14. An integrated (electro- and bio-oxidation) approach for remediation of industrial wastewater containing azo-dyes: Understanding the degradation mechanism and toxicity assessment.

    Science.gov (United States)

    Aravind, Priyadharshini; Selvaraj, Hosimin; Ferro, Sergio; Sundaram, Maruthamuthu

    2016-11-15

    A hybrid approach for the remediation of recalcitrant dye wastewater is proposed. The chlorine-mediated electrochemical oxidation of real textile effluents and synthetic samples (using Ti/IrO2-RuO2-TiO2 anodes), lead to discoloration by 92% and 89%, respectively, in 100min, without significant mineralization. The remediation was obtained through biodegradation, after removing the residual bio-toxic active chlorine species via sunlight exposition. Results show that the electrochemical discoloration enhances the effluent biodegradability with about 90% COD removal employing acclimatized naphthalene-degrading bacterial consortia, within 144h. Based on results obtained through FT-IR and GC-MS, it is likely that azo group stripping and oxidative cleavage of dyes occur due to the nucleophilic attack of active chlorine species during electro-oxidation. This leads to generation of aromatic intermediates which are further desulfonated, deaminated or oxidized only at their functional groups. These aromatic intermediates were mineralized into simpler organic acids and aldehydes by bacterial consortia. Phyto-toxicity trials on Vigna radiata confirmed the toxic nature of the untreated dye solutions. An increase in root and shoot development was observed with the electrochemically treated solutions, the same was higher in case of bio-treated solutions. Overall, obtained results confirm the capability of the proposed hybrid oxidation scheme for the remediation of textile wastewater. PMID:27427887

  15. Preparation and photocatalytic performance of Fe (III)-amidoximated PAN fiber complex for oxidative degradation of azo dye under visible light irradiation

    International Nuclear Information System (INIS)

    Polyacrylonitrile (PAN) fiber was modified with hydroxylamine hydrochloride to introduce amidoxime groups onto the fiber surface. These amidoxime groups were used to react with Fe (III) ions to prepare Fe (III)-amidoximated PAN fiber complex, which was characterized using SEM, XRD, FTIR, XPS, DMA, and DRS respectively. Then the photocatalytic activity of Fe-AO-PAN was evaluated in the degradation of a typical azo dye, C. I. Reactive Red 195 in the presence of H2O2 under visible light irradiation. Moreover, the effect of the Fe content of Fe-AO-PAN on dye degradation was also investigated. The results indicated that Fe (III) ions can crosslink between the modified PAN fiber chains by the coordination of Fe (III) ions with the amino nitrogen atoms and hydroxyl oxygen atoms of the amidoximation groups to form Fe (III)-amidoximated PAN fiber complex, and the Fe content of which is mainly determined by Fe (III) ions and amidoximation groups. Fe (III)-amidoximated PAN fiber complex is found to be activated in the visible light region. Moreover, Fe (III)-amidoximated PAN fiber complex shows the catalytic activity for dye degradation by H2O2 at pH = 6.0 in the dark, and can be significantly enhanced by increasing light irradiation and Fe content, therefore, it can be used as a new heterogeneous Fenton photocatalyst for the effective decomposition of the dye in water. In addition, ESR spectra confirm that Fe (III)-amidoximated PAN fiber complex can generate more ·OH radicals from H2O2 under visible light irradiation, leading to dye degradation. A possible mechanism of photocatalysis is proposed.

  16. High-energy irradiation treatment of aqueous solutions of C.I. Reactive Black 5 azo dye: pulse radiolysis experiments

    International Nuclear Information System (INIS)

    The reactions of the C.I. Reactive Black 5 with short lived eaq-, OH radical and H atom intermediates of water radiolysis in aqueous solution were investigated by pulse radiolysis with kinetic spectroscopic detection. The transients formed with the three intermediates have absorption maxima at ∼360, ∼410 and ∼470 nm. The eaq- adds to the azo group and the adduct radical anion rapidly protonates forming hydrazil radical. Based on the similar spectra similar intermediates are produced in H atom and hydrated electron reaction. The OH radical most probably adds to the azo group, however, it attacks also the aromatic rings. The strong absorbance found is attributed to the high conjugation of the radical site with the aromatic rings

  17. Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv

    Science.gov (United States)

    2012-01-01

    In the present study, the decolorization and degradation of Reactive Black 5 (RB5) azo dye was investigated by biological, photocatalytic (UV/TiO2) and combined processes. Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation of the aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2). COD (chemical oxygen demand) was not detectable after complete decolorization of 50 mg/L RB5 solution. However, photocatalytic process was not effective in the removal of the dye at high concentrations (≥200 mg/L). With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 h illumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings) was not completely removed. A two-step treatment process, namely, biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5), absorbance peak in UV region significantly disappeared after 2 h illumination and about 60% COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings. PMID:23369285

  18. Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv

    Directory of Open Access Journals (Sweden)

    Narjes Jafari

    2012-12-01

    Full Text Available In the present study, the decolorization and degradation of Reactive Black 5 (RB5 azo dye was investigated by biological, photocatalytic (UV/TiO2 and combined processes.Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation ofthe aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2. COD (chemical oxygen demand wasnot detectable after complete decolorization of 50 mg/L RB5 solution. However,photocatalytic process was not effective in the removal of the dye at high concentrations (≥200 mg/L. With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 hillumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings was not completely removed. A two-step treatment process, namely,biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5, absorbance peak in UV region significantly disappeared after 2 h illumination and about 60 % COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings.

  19. Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv

    Directory of Open Access Journals (Sweden)

    Jafari Narjes

    2012-12-01

    Full Text Available Abstract In the present study, the decolorization and degradation of Reactive Black 5 (RB5 azo dye was investigated by biological, photocatalytic (UV/TiO2 and combined processes. Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation of the aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2. COD (chemical oxygen demand was not detectable after complete decolorization of 50 mg/L RB5 solution. However, photocatalytic process was not effective in the removal of the dye at high concentrations (≥200 mg/L. With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 h illumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings was not completely removed. A two-step treatment process, namely, biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5, absorbance peak in UV region significantly disappeared after 2 h illumination and about 60% COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings.

  20. Hydrogen bonding intermolecular effect on electro-optical response of doped 6PCH nematic liquid crystal with some azo dyes

    Science.gov (United States)

    Kiani, S.; Zakerhamidi, M. S.; Tajalli, H.

    2016-05-01

    Previous studies on the electro-optical responses of dye-doped liquid crystal have shown that dopant material have a considerable effect on their electro-optical responses. Despite the studies carried out on electro-optical properties of dye-doped liquid crystal, no attention has been paid to study of the interaction and structural effects in this procedure. In this paper, linear dyes and with similar structure were selected as dopants. The only difference in used dyes is the functional groups in their tails. So, doping of these dyes into liquid crystals determines the influence of interaction type on electro-optical behaviours of the doped systems. Therefore, in this work, two aminoazobenzene ("A-dye": hydrogen bond donor) and dimethyl-aminoazobenzene ("B-dye") dyes with different compositional percentages in liquid crystal host were used. Electro-optical Kerr behaviour, the pre-transition temperature and third order nonlinear susceptibility were investigated. The obtained results effectively revealed that type of interactions between the dye and liquid crystal is determinative of behavioral difference of doped system, compared to pure liquid crystal. Also, pre-transitional behaviour and thereupon Kerr electro-optical responses were affected by formed interactions into doped systems. In other words, it will be shown that addition of any dopants in liquid crystal, regardless of the nature of interactions, cannot cause appropriate electro-optical responses. In fact, type of dye, nature of interactions between dopant and liquid crystalline host as well as concentration of dye are the key factors in selecting the appropriate liquid crystal and dopant dye.

  1. Potential of the aquatic fern Azolla filiculoides in biodegradation of an azo dye: modeling of experimental results by artificial neural networks.

    Science.gov (United States)

    Khataee, A R; Movafeghi, A; Vafaei, F; Lisar, S Y Salehi; Zarei, M

    2013-01-01

    The potential of an aquatic fern, Azolla filiculoides, in phytoremediation of a mono azo dye solution, C.I. Acid Blue 92 (AB92), was studied. The effects of operational parameters such as reaction time, initial dye concentration, fern fresh weight, pH, temperature and reusability of the fern on biodegradation efficiency were investigated. The intermediate compounds produced by biodegradation process were analyzed using GC-MS analysis. An artificial neural network (ANN) model was developed to predict the biodegradation efficiency. The findings indicated that ANN provides reasonable predictive performance (R2 = 0.961). The effects of AB92 solutions (10 and 20 mg L(-1)) on growth, chlorophylls and carotenoids content, activity of antioxidant enzymes such as superoxide dismutase, peroxidase and catalase and formation of malondialdehyde were analyzed. AB92 generally showed inhibitory effects on the growth. Moreover, photosynthetic pigments in the fronds significantly decreased in the treatments. An increase was detected for lipid peroxidation and antioxidant enzymes activity, suggesting that AB92 caused reactive oxygen species production in Azolla fronds, which were scavenged by induced activities of antioxidant enzymes. PMID:23819271

  2. Novel acid mono azo dye compound: Synthesis, characterization, vibrational, optical and theoretical investigations of 2-[(E)-(8-hydroxyquinolin-5-yl)-diazenyl]-4,5-dimethoxybenzoic acid

    Science.gov (United States)

    Saçmacı, Mustafa; Çavuş, Hatice Kanbur; Arı, Hatice; Şahingöz, Recep; Özpozan, Talat

    2012-11-01

    Novel acid mono azo dye, 2-[(E)-(8-hydroxyquinolin-5yl)-diazenyl]-4,5-dimethoxybenzoic acid (HQD), was synthesized by coupling diazonium salt solution of 2-amino-4,5-dimethoxybenzoic acid (DMA) with 8-hydroxyquinoline (HQ). This dye was characterized by UV-vis, IR & Raman, 1H and 13C NMR spectroscopic techniques and elemental analysis. The normal coordinate analysis of HQD was also performed to assign each band in vibrational spectra. DFT (B3LYP and B3PW91) calculations were employed to optimize the geometry, to interpret NMR spectra, to calculate and to determine the stable tautomeric structure of the compound. Natural Bond Orbital (NBO) analysis was performed to investigate intramolecular interactions. The vibrational spectral data obtained from solid phase IR & Raman spectra were assigned based on the results of the theoretical calculations. UV-vis spectroscopic technique was employed to obtain the optical band gap of HQD. The analysis of the optical absorption data revealed the existence of direct and indirect transitions in the optical band gaps. The optical band gaps of HQD have been found 1.95 and 1.90 eV for direct and indirect transitions, respectively.

  3. Photoassisted electrochemical recirculation system with boron-doped diamond anode and carbon nanotubes containing cathode for degradation of a model azo dye

    International Nuclear Information System (INIS)

    In this research work, a photoassisted electrochemical system under recirculation mode and with UV irradiation was designed for treatment of C.I. Acid Blue 92 (AB92) as a model anionic azo dye in aqueous solution. Degradation experiments were carried out with boron-doped diamond (BDD) anode and carbon nanotubes-polytetrafluoroethylene (CNTs-PTFE) cathode in the presence of sulfate as an electrolyte. A comparative study of AB92 degradation by photolysis, electrochemical oxidation and photoassisted electrochemical processes after 45 min of treatment demonstrated that degradation efficiency was 27.89, 37.65 and 95.86%, respectively. Experimental data revealed that the degradation rate of AB92 in all of the processes obeyed pseudo-first-order kinetics and application of photoassisted electrochemical system reduced electrical energy per order (EEO), considerably. Degradation efficiency of photoassisted electrochemical process enhanced by increasing applied current and flow rate values, but vice versa trend was observed for initial dye concentration and an optimum amount of 6 was obtained for initial pH. The TOC measurement results demonstrated that 93.24% of organic substrates were mineralized after 120 min of photoassisted electrochemical process and GC–Mass analysis was performed for identification of degradation intermediates

  4. Efeitos de agentes oxidantes e oxigênio dissolvido na descoloração do azo corante acid orange 7 por fotólise e fotocatálise Effects of oxidant agents and dissolved oxygen on the decolorization of acid orange 7 azo dye by photolysis and photocatalysis

    Directory of Open Access Journals (Sweden)

    Adriana Campano Lucilha

    2009-01-01

    Full Text Available The decolorization of acid orange 7 azo dye by photolysis and photocatalysis by ZnO was investigated in the presence of oxidants such as NaClO3, NaBrO3, NaIO4, and K2S2O8 in an open reactor at 30 ºC. The decolorization was relatively fast at lower oxidants concentrations and slow rate at larger concentrations, except for persulfate in the photocatalysis. Concerning photolysis the rate constant enhanced gradually, except for chlorate, outreaching the obtained values by photocatalysis, at higher concentrations. The air saturation decreased the rate constant in both processes and indicated that the azo dye can be decolorized without dissolved oxygen in persulfate medium.

  5. Photo-electrochemical studies of chemically deposited nanocrystalline meso-porous n-type TiO2 thin films for dye-sensitized solar cell (DSSC) using simple synthesized azo dye

    Science.gov (United States)

    Ezema, C. G.; Nwanya, A. C.; Ezema, B. E.; Patil, B. H.; Bulakhe, R. N.; Ukoha, P. O.; Lokhande, C. D.; Maaza, Malik; Ezema, Fabian I.

    2016-04-01

    Nanocrystalline titanium dioxide (TiO2) thin films were deposited by successive ionic layer adsorption and reaction method onto fluorine doped tin oxide coated glass substrate at room temperature (300 K). Titanium trichloride and sodium hydroxide were used as cationic and anionic sources, respectively. The as-deposited and annealed films were characterized for structural, morphological, optical, electrical and wettability properties. The photoelectrochemical study of TiO2 sensitized with a laboratory synthesized organic dye (azo) was evaluated in the polyiodide electrolyte at 40 mW cm-2 light illumination intensity. The photovoltaic characteristics show a fill factor of 0.24 and solar conversion efficiency value of 0.032 % for a TiO2 thickness of 0.96 µm as compared to efficiency of 0.014 % for rose Bengal of the same thickness.

  6. Several Issues on the Detection of Banned Azo Dyes in Textiles%浅析纺织品禁用偶氮染料检测的若干问题

    Institute of Scientific and Technical Information of China (English)

    郭建峰

    2014-01-01

    This paper made a brief introduction to the hot and difficult issues in detection of banned azo dyes in textile, and proposed concrete solutions.%本文针对纺织品禁用偶氮染料检测的热点难点问题,做了简要介绍分析并提出了具体的解决方案。

  7. STUDI DEGRADASI ZAT PEWARNA AZO, METIL ORANYE MENGGUNAKAN FERRAT (FeO42-)

    OpenAIRE

    Dian Windy Dwiasi; Mardiyah Kurniasih

    2008-01-01

    Synthesis of ferrate and its application to azo dyes degradation have been investigated. The synthesis was carried out by reacting Fe(NO3)3 solution with NaOCl in alkaline condition. Oxidation reaction of azo dyes was carried out by adjusting the molar ratio of ferrate to azo dyes. When ferrate reacted with azo dyes, its absorbance was monitored using UV-Vis spectrophotometer at pH condition that had been optimized. Kinetics study for azo dyes degradation was carried out at the absorbance max...

  8. Enzymatic reduction of azo and indigoid compounds

    OpenAIRE

    Pricelius, S.; Held, C; Murkovic, M.; Bozic, M.; Kokol, V.; Paulo, Artur Cavaco; Gübitz, Georg M.

    2007-01-01

    A customer- and environment-friendly method for the decolorization azo dyes was developed. Azoreductases could be used both to bleach hair dyed with azo dyes and to reduce dyes in vat dyeing of textiles. A new reduced nicotinamide adenine dinucleotide-dependent azoreductase of Bacillus cereus, which showed high potential for reduction of these dyes, was purified using a combination of ammonium sulfate precipitation and chromatography and had a molecular mass of 21.5 kDa. The optimum pH of the...

  9. STUDI DEGRADASI ZAT PEWARNA AZO, METIL ORANYE MENGGUNAKAN FERRAT (FeO42-

    Directory of Open Access Journals (Sweden)

    Dian Windy Dwiasi

    2008-05-01

    Full Text Available Synthesis of ferrate and its application to azo dyes degradation have been investigated. The synthesis was carried out by reacting Fe(NO33 solution with NaOCl in alkaline condition. Oxidation reaction of azo dyes was carried out by adjusting the molar ratio of ferrate to azo dyes. When ferrate reacted with azo dyes, its absorbance was monitored using UV-Vis spectrophotometer at pH condition that had been optimized. Kinetics study for azo dyes degradation was carried out at the absorbance maximum of azo dyes, as a function of time. Ferrate can oxidize azo dyes, methyl oranye effectively in optimum pH of 9.6. With the molar ratio of ferrate/azo dyes 5/1, it showed that the percentages of methyl oranye degradation reached 100%. The azo dyes degradation followed first order of kinetics. Analysis using UV-Vis spectrofotometry suggests that the products of azo dyes degradation are nitrate, ammonia, and benzene. This results showed that ferrate is an alternative and green oxidizing agent which can be used for azo dyes degradation.

  10. Characterization and performance of carbonaceous materials obtained from exhausted sludges for the anaerobic biodecolorization of the azo dye Acid Orange II

    International Nuclear Information System (INIS)

    Graphical abstract: - Highlights: • Carbonaceous materials were prepared from exhausted sludge materials. • High surface area and good physicochemical properties were achieved. • Utilization of waste sludge materials and mixed anaerobic cultures were used in a continuous anaerobic UPBR system (upflow packed bed biological reactor). • Effective treatment of dye contaminated wastewater in a cheapest and environmental friendly method was demonstrated. - Abstract: This work presents the preliminary study of new carbonaceous materials (CMs) obtained from exhausted sludge, their use in the heterogeneous anaerobic process of biodecolorization of azo dyes and the comparison of their performance with one commercial active carbon. The preparation of carbonaceous materials was conducted through chemical activation and carbonization. Chemical activation was carried out through impregnation of sludge-exhausted materials with ZnCl2 and the activation by means of carbonization at different temperatures (400, 600 and 800 °C). Their physicochemical and surface characteristics were also investigated. Sludge based carbonaceous (SBC) materials SBC400, SBC600 and SBC800 present values of 13.0, 111.3 and 202.0 m2/g of surface area. Biodecolorization levels of 76% were achieved for SBC600 and 86% for SBC800 at space time (τ) of 1.0 min, similar to that obtained with commercial activated carbons in the continuous anaerobic up-flow packed bed reactor (UPBR). The experimental data fit well to the first order kinetic model and equilibrium data are well represented by the Langmuir isotherm model. Carbonaceous materials show high level of biodecolorization even at very short space times. Results indicate that carbonaceous materials prepared from sludge-exhausted materials have outstanding textural properties and significant degradation capacity for treating textile effluents

  11. Optimization of working cathode position in sleeve-type bioelectrochemical system with inner chamber/outer chamber for azo dye treatment.

    Science.gov (United States)

    Kong, Fanying; Wang, Aijie; Ren, Hong-Yu

    2015-12-01

    In this study, the optimization of working cathode position in sleeve-type bioelectrochemical system (BES) was evaluated with inner/outer chamber for azo dye decolorization. Results showed that the working position in outer chamber performed better with decolorization efficiencies of 97.8 ± 2.1% (7h) and 94.0 ± 2.3% (16 h) than that in inner chamber as the volume ratio Vcathode:Vanode=1:1 and 3:1, respectively. The current and electrochemical impedance spectroscopy (EIS) analysis indicated that the proton/electron transfer and anolyte diffusion could be improved using outer chamber as working position. The decolorization with increased volume ratio could be further improved through the strategy of increasing substrate concentration, which would provide enough electrons and decrease diffusion resistance, further improving the whole performance with increased outer cathode volume. It has the great potential in sleeve-type configuration application and would create more challenges for process optimization and maintenance. PMID:26409856

  12. Multi-scale biomarker evaluation of the toxicity of a commercial azo dye (Disperse Red 1) in an animal model, the freshwater cnidarian Hydra attenuata.

    Science.gov (United States)

    de Jong, Laetitia; Pech, Nicolas; de Aragão Umbuzeiro, Gisela; Moreau, Xavier

    2016-06-01

    Acute (24 h, 48 h, 72 h) and chronic (7 days) tests have been performed to evaluate the effects of the commercial azo dye Disperse Red 1 (DR1) using various biomarkers in the freshwater invertebrate Hydra attenuata. Morphological changes have been selected to calculate ecotoxicological thresholds for sublethal and lethal DR1 concentrations. A multinomial logistic model showed that the probability of each morphological stage occurrence was function of concentration, time and interaction between both. Results of oxidative balance parameter measurements (72 h and 7 days) suggest that polyps set up defense mechanisms to limit lipid peroxidation caused by DR1. DR1 exposure at hormetic concentrations induces increase of asexual reproductive rates. This result suggests (1) an impact on the fitness-related phenotypical traits and (2) trade-offs between reproduction and maintenance to allow the population to survive harsher conditions. Changes in serotonin immuno-labeling in polyps showing alterations in feeding behavior suggest that chronic DR1 exposure impaired neuronal processes related to ingesting behavior in H. attenuata. This ecotoxicity study sheds light on the possible serotonin function in Hydra model and reports for the first time that serotonin could play a significant role in feeding behavior. This study used a multi-scale biomarker approach investigating biochemical, morphological, reproductive and behavioral endpoints in Hydra attenuata. This organism is proposed for a pertinent animal model to assess ecotoxicological impact of pollutant mixtures in freshwater environment. PMID:27019466

  13. [Characterization of cases contravening of regulations regarding primary aromatic amines originating from azo dyes in commercial textile products and leather products in European Union].

    Science.gov (United States)

    Kawakami, Tsuyoshi; Isama, Kazuo; Ikarashi, Yoshiaki

    2013-01-01

    Contraventions of regulations regarding primary aromatic amines (PAAs) originating from azo dyes in commercial textile products and leather products in European Union (EU), notified in the period between 2006 and 2012 were collected from the Rapid Alert System for non-food consumer products (RAPEX), were characterized. Various types of products (clothes, footwear, bedding, etc.) and their raw materials (cotton, silk, viscose, leather, etc.) were reported to have contravened the regulations. The contravention frequencies for products made in China and India were higher than those for other countries. Ten percentage of the country in which the reported products were produced was unknown. The notification frequencies for benzidine and 4-aminoazobenzene were higher than those for other PAAs. Contravention of regulations regarding benzidine, 4-aminoazobenzene, and 3,3'-dimethoxybenzidine were notified every year. Contraventions of regulations regarding five PAAs--classified as IARC group 1--were notified one or several times. Since the scale of the survey conducted in Japan were small compared with RAPEX, it is necessary that many kinds and number of products should be surveyed in Japan. In addition, it is also necessary to pay attention to 4-aminoazobenzene, while it has not been detected in the previous studies conducted in Japan. PMID:24340672

  14. Syntheses, Spectral, Surface Morphological and Gamma Ray Irradiation Studies of Some Oxomolybdenum(V) and Dioxomolybdenum(VI) Complexes of an Azo Dye Derived from 4-aminoantipyrine

    International Nuclear Information System (INIS)

    Syntheses of some novel oxomolybdenum(V) and dioxomolybdenum(VI) complexes with an azo dye meth-oxyphenolazoantipyrine (HL) derived from 4-aminoantipyrine and 2-methoxyphenol are reported. The complexes have been characterized by elemental analyses, molar conductance, magnetic susceptibility data, IR, UV-Vis, 1H NMR, EPR and FAB mass spectral studies. The physicochemical studies and spectral data indicate that HL acts as a bidentate chelating ligand. The complexes have the general formulae [MoO(HL)XCl2] and [MoO2(HL)XCl],where X=Cl, NCS or NO3. All the complexes are found to have distorted octahedral geometry. Structural and morphological characterization of the complexes [MoO(HL)Cl3](1) and [MoO2(HL)Cl2](4) before and after gamma ray irradiation,was performed by X-ray diffraction and scanning electron microscopy(SEM). The ligand and the complexes were screened for their possible antimicrobial activities

  15. GONADAL EFFECTS OF FETAL EXPOSURE TO THE AZO DYE CONGO RED IN MICE: INFERTILITY IN FEMALE BUT NOT MALE OFFSPRING

    Science.gov (United States)

    The present study describes the relationship between gonadal genesis and fertility in male and female mice exposed in utero to the diazo dye Congo red (CR). aternal CR treatment inhibited testicular and ovarian function in the offspring after oral administration of I or 0.5 g/kg/...

  16. Decolorization of azo dyes with high salt concentration by salt-tolerant mixed cultures under anaerobic conditions

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-bo; ZHOU Ji-ti; WANG Dong; WANG Jing; YU Hui; SONG Zhi-yong

    2005-01-01

    Because the lack of detailed study of biological decolorization in high salt dye wastewater, it is still difficult to evaluate the biological treatment on high-salinity dye wastewater. The experiments were carried out to study the salt-tolerant bacteria, which is useful in the treatment of high-salinity colored wastewater. Simulated wastewater containing 5-150 g/L salt (NaCl) and 50-2000 mg/L Reactive Brilliant Red K-2BP was treated with three salt-tolerant mixed cultures (CAS, TAS, DSAS), which were under a gradually acclimated procedure. With the increase of concentrations of salt and dye, the decolorization became low. The abilities of decolorization of dyes wastewater by three mixed cultures (CAS, TAS, DSAS) were studied, CAS and DSAS mixed cultures showed more active for the treatment of high-salinity colored wastewater than TAS mixed cultures. The results suggested that there might be a simple process for the high salt wastewater treatment, which could be incorporated into conventional activated sludge plants.

  17. New azo dyes as colored isoelectric point markers for isoelectric focusing in acidic pH region

    Czech Academy of Sciences Publication Activity Database

    Šťastná, Miroslava; Trávníček, Martin; Šlais, Karel

    2005-01-01

    Roč. 26, č. 1 (2005), s. 53-59. ISSN 0173-0835 R&D Projects: GA AV ČR(CZ) IBS4031201; GA ČR(CZ) GA203/02/1447; GA AV ČR IAA4031302 Keywords : ampholytic dyes * pI markers Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.850, year: 2005

  18. Enhanced photocatalytic activity and stability of alumina supported hematite for azo-dye degradation in aerated aqueous suspension

    International Nuclear Information System (INIS)

    Highlights: • Alumina supported hematite is much more active than bare hematite. • This catalyst is also more active and stable than silica supported hematite. •The particle size of hematite on the supported catalyst is obviously reduced. • The adsorption of anionic dye on alumina-supported catalyst is notably enhanced. -- Abstract: Silica supported hematite (Fe2O3/silica) that is more active but less stable than the supported hematite for organic photodegradation in aqueous solution has been reported. In this work, we report on alumina supported hematite (Fe2O3/alumina) with significantly improved activity and stability. The catalysts were prepared by mixing alumina with a pre-made colloidal iron oxide at various loading (0–100 wt %), followed by sintering at different temperatures (200–900 °C). Solid characterization with X-ray diffraction and N2 adsorption showed that hematite particles were small in size, and large in surface area, as compared with the unsupported hematite prepared in parallel. The catalyst activity was evaluated with anionic Orange II as a model substrate, and the reaction was carried out in aerated aqueous suspension under light irradiation at wavelengths longer than 320 nm. As the Fe2O3 loading on alumina or the catalyst sintering temperature increased, the apparent rate constant of dye degradation increased, and then decreased. The maximum rate of dye degradation was obtained with 25 wt % Fe2O3/alumina, sintered at 400 °C. Moreover, five consecutive experiments for dye photodegradation showed that Fe2O3/alumina was much more stable than Fe2O3/silica, due to alumina that has a positively charged surface and thus facilitates the dissolved iron species back onto iron oxide. The higher activity of Fe2O3/alumina than Fe2O3/silica and bare hematite is ascribed to the combined effect between the reduced particle size of hematite and the enhanced surface adsorption of dye on the catalyst

  19. Effect of AZO on GO-NO-GO radiation indicator

    International Nuclear Information System (INIS)

    The purpose of the study is to evaluate the effect of Azo group dyes as an radiation indicator. Dimethyl Yellow, Alizarin Red, Congo Red, Methyl Violet and Bromophenol Blue dyes were used to compare the capability of each dye to change colour in response to radiation. Sensitivity of single and incorporated dyes were identified by exposing them to 5-50 kGy gamma radiation. The result shows that the Azo group is more sensitive to radiation compare to other groups. (Author)

  20. Assessment of toxicity and genotoxicity of the reactive azo dyes Remazol Black B and Remazol Orange 3R and effectiveness of electron beam irradiation in the reduction of color and toxic effects

    International Nuclear Information System (INIS)

    The textile industries play an important role in national and global economy. But, their activities are considered potentially polluting. The use of large volumes of water and the production of colored wastewater with high organic matter are among the main issues raised, especially during the stage of dyeing and washing of the textile process. The reactive azo dyes are the main colors used in the industry for dyeing of cotton in Brazil and worldwide. Because of its low setting and variations in the fiber production process, about 30% of the initial concentration used in the dyeing baths are lost and will compose the final effluent. These compounds have a low biodegradability, are highly soluble in water and therefore are not completely removed by conventional biological processes. In addition, other processes do not promote degradation but the transference to solid environment. The dyes discarded without treatment in the water body can cause aesthetic modifications, alter photosynthesis and gas solubility, as well as being toxic and genotoxic. The main objectives of this study were to evaluate the toxicity and genotoxicity of two reactive azo dyes (Remazol Black B - RPB and Remazol Orange 3R - R3AR) and the percentage of color and toxicity reduction after the use of electron beam radiation. The acute toxicity assays performed with Vibrio fischeri, Daphnia similis and Biomphalaria glabrata showed different response patterns for dyes. The different chemical forms of dyes were slightly toxic to Vibrio fischeri and only the RPB dye (vinylsulphone) was toxic (EC5015min = 6,23 mg L-1). In tests with Daphnia similis, the dye RPB was slightly toxic in its pattern form, sulphatoethylsulphone, (CE5048h = 91,25 mg L-1) and showed no toxicity in other chemical forms. However, the RA3R dye was toxic to the dafnids and the vinylsulphone form very toxic (EC5048h = 0,54 mg L-1). No toxicity was observed in Biomphalaria glabrata assays. Chronic toxicity was assessed with the

  1. New pathway for degradation of sulfonated azo dyes by microbial peroxidases of Phanerochaete chrysosporium and Streptomyces chromofuscus.

    OpenAIRE

    Goszczynski, S; Paszczynski, A; Pasti-Grigsby, M B; Crawford, R L; Crawford, D. L.

    1994-01-01

    Pathways for the degradation of 3,5-dimethyl-4-hydroxy-azobenzene-4'-sulfonic acid (I) and 3-methoxy-4-hydroxyazobenzene-4'-sulfonamide (II) by the manganese peroxidase and ligninase of Phanerochaete chrysosporium and by the peroxidase of Streptomyces chromofuscus have been proposed. Twelve metabolic products were found, and their mechanisms of formation were explained. Preliminary oxidative activation of the dyes resulted in the formation of cationic species, making the molecules vulnerable ...

  2. Detoxification of azo dyes by a novel pH-versatile, salt-resistant laccase from Streptomyces ipomoea

    OpenAIRE

    Molina-Guijarro, Jos?? M.; P??rez Torres, Juana; Mu??oz-Dorado, Jos??; Guill??n Carretero, Francisco; Moya Lobo, Raquel; Hern??ndez Cutuli, Manuel; Arias Fern??ndez, Mar??a Enriqueta

    2009-01-01

    A newly identified extracellular laccase produced by Streptomyces ipomoea CECT 3341 (SilA) was cloned and overexpressed, and its physicochemical characteristics assessed together with its capability to decolorize and detoxify an azotype dye. Molecular analysis of the deduced sequence revealed that SilA contains a TAT-type signal peptide at the N-terminus and only two cupredoxine domains; this is consistent with reports describing two other Streptomyces laccases but contrasts with ...

  3. Monopolar Electro-Coagulation Process for Azo Dye C.I. Acid Red 18 Removal from Aqueous Solutions

    OpenAIRE

    Ghasem Azarian; Davood Nematollahi; Ali Reza Rahmani; Kazem Godini; Mohammad Bazdar; Hassan Zolghadrnasab

    2014-01-01

    The discharge of wastewaters containing an untreated dye results in aesthetic problems and an increase in gases solubility, which causes light transmission inhibition into water bodies. In spite of advantages of physicochemical and biological methods, these processes produce huge amounts of sludge, toxic by-products and require several oxidant chemicals. By contrast, electrochemical processes because of their high versatility, high efficiency and eco-friendly properties are more acceptable. I...

  4. Synthesis, structural characterization of nano ZnTiO3 ceramic: An effective azo dye adsorbent and antibacterial agent

    Directory of Open Access Journals (Sweden)

    R.S. Raveendra

    2014-12-01

    Full Text Available Nanocrystalline meta-zinc titanate (ZnTiO3 ceramic was prepared using a self-propagating solution combustion synthesis (SCS for the first time using urea as fuel. The product was calcined at 800 °C for 2 h to improve the crystallinity. Powder X-ray diffraction (PXRD, Fourier transform infrared spectroscopy (FTIR, scanning electron microscopy (SEM, energy-dispersive X-ray spectroscopy (EDAX, high resolution transmission electron microscopy (HR-TEM and UV–vis absorption spectroscopy were used to characterize the final product. PXRD results show that the ilmenite type rhombohedral structure was formed when the sample was calcined at 800 °C for 2 h. Adsorption experiments were performed with cationic malachite green (MG dye. ∼96% dye was adsorbed onto nanocrystalline ZnTiO3 ceramic at pH 9 for 30 min of the contact time. The optimum adsorbent dose was found to be 0.45 g/L of dye. Langmuir–Hinshelwood model was used to study adsorption kinetics and first order kinetic model best describes the MG adsorption on ZnTiO3. Antibacterial activity was investigated against gram negative Klebsiella aerogenes, Pseudomonas desmolyticum, Escherichia coli, and gram positive Staphylococcus aureus bacteria by agar well diffusion method. Nanocrystalline ZnTiO3 ceramic showed significant effect on all the four bacterial strains at the concentration of 1000 and 1500 μg per well.

  5. Removal of binary azo dyes from water by UV-irradiated degradation in TiO2 suspensions

    International Nuclear Information System (INIS)

    Photodegradation and mineralization of single and binary Acid Orange 7 (AO7) and Reactive Red 2 (RR2) under UV irradiation in TiO2 suspensions was examined. Experiments were conducted as a function of initial pH, TiO2 dose, and initial dye concentration. First-order derivative spectrophotometric method was used to simultaneously analyze AO7 and RR2 in binary solutions. The Langmuir-Hinshelwood kinetic model was applied to evaluate and compare the apparent rate constants for the photodegradation of both dyes in single and binary solutions. It was shown that photodegradation of both dyes in binary solution was slower than those in single solution under comparable conditions. Moreover, the difference between the apparent rate constants of RR2 and AO7 became smaller in contrast to the cases of single solutions. After 20-min UV irradiation with 0.5 g/L TiO2, complete removal of single 0.086 mM AO7 and 0.086 mM RR2 at pH 6.8 was obtained, but only 60% and 45% of binary 0.086 mM AO7 and 0.086 mM RR2 was removed, respectively.

  6. Synthesis, Characterization, and Biological Activity of 5-Phenyl-1,3,4-thiadiazole-2-amine Incorporated Azo Dye Derivatives

    Directory of Open Access Journals (Sweden)

    Chinnagiri T. Keerthi Kumar

    2013-01-01

    Full Text Available 5-Phenyl-1,3,4-thiadiazole-2-amine has been synthesized by single step reaction. A series of heterocyclic azodyes were synthesized by diazotisation of 5-phenyl-1,3,4-thiadiazole-2-amine by nitrosyl sulphuric acid followed by coupling with different coupling compounds such as 8-hydroxyquinoline, 2,6-diaminopyridine, 2-naphthol, N,N-dimethyl aniline, resorcinol, and 4,6-dihydroxypyrimidine. The dyes were characterized by UV-Vis, IR, 1H-NMR, 13C NMR, and elemental analysis. The synthesized compounds were also screened for biological activity.

  7. Photodegradation of azo dye Congo Red from aqueous solution by the WO3-TiO2/activated carbon (AC) photocatalyst under the UV irradiation

    International Nuclear Information System (INIS)

    The WO3-TiO2/AC (activated carbon) photocatalyst used in the experiment was prepared by the sol-gel-dipping-calcination method. The photocatalyst was characterized by XRD and the photoactivity of it was tested by the degradation of azo dye Congo Red. In order to obtain the optimum preparation conditions of the photocatalyst and the optimum degradation conditions of Congo Red, two orthogonal tests have been applied. The results showed that the optimal preparation conditions of the photocatalyst were: calcination temperature 500 deg. C, the content of WO3 3% and the hours of calcination 3 h and the optimal conditions of Congo Red degradation were: the dosage of catalyst 10 g L-1, pH 7 and the amount of H2O2 114 mM. The effect of several co-existing negative ions on the photodegradation of Congo Red was investigated. It was found that ClO2-, BrO3- and S2O82- had a positive effect on the photodegradation of Congo Red in the following order: S2O82- > ClO2- > BrO3-. On the contrary, the anions such as SO42-, NO3-, Cl-, SO32-, H2PO4- decreased the photodecolorization percent of Congo Red. Their inhibitory effect were in the order SO32- > Cl- > H2PO4- > SO42- > NO3-. Finally, the kinetics process was studied and the photodegradation rate of Congo Red was found to obey pseudo-first-order kinetics equation represented by the Langmuir-Hinshelwood model

  8. Decolorization characteristics of a newly isolated salt-tolerant Bacillus sp. strain and its application for azo dye-containing wastewater in immobilized form.

    Science.gov (United States)

    Yu, Lei; Zhang, Xiao-Yu; Tang, Qing-Wen; Li, Jia; Xie, Tian; Liu, Chang; Cao, Ming-Yue; Zhang, Rui-Chang; Wang, Shi; Hu, Jin-Mei; Qiao, Wei-Chuan; Li, Wen-Wei; Ruan, Hong-Hua

    2015-11-01

    Strain CICC 23870 capable of decolorization of various azo dyes under high saline conditions was isolated from saline-alkali soil. The oxygen-insensitive azoreductase in crude extracts exhibited a wide substrate adaptively in the presence of NADH as a cofactor. The decolorization process by free cells followed first-order kinetics, with a high Methyl Orange (MO) tolerance concentration up to 100 mg l(-1) estimated by Haldane model. The average decolorization rate of free cell system was 26.30 mg g(-1) h(-1) at initial MO concentration of 32.7 mg l(-1). However, the values for the systems of immobilized cells (4 mm) in alginate, alginate and nano-TiO2, and alginate and powered activated carbon (PAC) were 6.83, 4.64, and 11.34 mg g(-1) h(-1), respectively. The effective diffusion factors in the tree different matrices were calculated by diffusion-based mathematic model. The diffusion step controls the overall decolorization rate, and the effective diffusion coefficients varied with internal structure of the bead matrices. The diffusion coefficients were increased from 4.98 × 10(-9) to 2.25 × 10(-8) cm(2) s(-1) when PAC was added, but decreased to 6.62 × 10(-10) cm(2) s(-1) when nano-TiO2 was added. The immobilized matrices could be reused for at least three cycles but with a decreased decolorization rate, possibly due to the breakage of beads at the end of each cycle, which led to the loss of immobilized bacteria. PMID:26175104

  9. Enhanced degradation of azo dye in wastewater by pulsed discharge plasma coupled with MWCNTs-TiO2/γ-Al2O3 composite photocatalyst.

    Science.gov (United States)

    Li, Xin; Wang, Tiecheng; Qu, Guangzhou; Liang, Dongli; Hu, Shibin

    2016-05-01

    In order to improve the photocatalytic performance of TiO2 in pulsed discharge plasma systems, easily recycled multi-walled carbon nanotubes (MWCNTs)-TiO2 supported on γ-Al2O3 (MWCNTs-TiO2/γ-Al2O3) composite photocatalyst were prepared. The morphology and physicochemical properties of the prepared catalysts were investigated using XRD, SEM, FTIR and UV-vis spectroscopy. The photocatalytic activity was evaluated by degradation of azo dye acid orange II (AO7) in wastewater under pulsed discharge plasma. The results indicate that the MWCNTs-TiO2/γ-Al2O3 composite catalyst possesses enhanced photocatalytic activity facilitating the decomposition of AO7 compared with TiO2/γ-Al2O3 composite in pulsed discharge plasma systems. Under pulsed discharge plasma, almost 100% AO7 is degraded by the MWCNTs-TiO2/γ-Al2O3 composite after 60 min at optimal conditions. The degradation efficiency of AO7 is also affected by the dosage of the composite catalyst and pulsed discharge peak voltage. As the amount of MWCNTs-TiO2/γ-Al2O3 composite and pulsed discharge peak voltage increases, the degradation efficiency of AO7 increases. The photocatalyst was implemented for 6 cycles and the degradation efficiency of AO7 remains higher than 85% under pulsed discharge plasma. Results indicate that the catalyst displays easy separation and minimal deactivation after several uses. Possible decomposition mechanisms were also investigated. MWCNTs are capable of improving the photocatalytic activity of TiO2/γ-Al2O3 composite in pulsed discharge plasma systems primarily due to the photo-induced-electron absorption effect and the electron trap effect of MWCNTs. The results of this study establish the feasibility and potential implementation of MWCNTs-TiO2/γ-Al2O3 composites in pulsed discharge plasma systems for the degradation of dye wastewater. PMID:26946167

  10. Photocatalytic degradation of textile azo dye over Ce1-xSn xO2 series

    International Nuclear Information System (INIS)

    Ce1-xSn xO2 (x = 0, 0.1, 0.2, 0.3 and 1.0) have been prepared by co-precipitation method and characterized by XRD, FTIR, BET surface area and TG/DSC methods. The solid state studies such as electrical resistivity, magnetic susceptibility and diffuse reflectance measurements have been carried out and are attempted to correlate with the photocatalytic activity of these compositions. Solar radiation induced degradation of the textile diazo dye Naphthol Blue Black (NBB) has been carried out on these semiconductor compositions. The surface adsorbed oxygen plays an important role in scavenging photogenerated electrons thus preventing the recombination between electron and hole, inducing effective photodegradation

  11. Thermal modification of activated carbon surface chemistry improves its capacity as redox mediator for azo dye reduction.

    Science.gov (United States)

    Pereira, L; Pereira, R; Pereira, M F R; van der Zee, F P; Cervantes, F J; Alves, M M

    2010-11-15

    The surface chemistry of a commercial AC (AC(0)) was selectively modified, without changing significantly its textural properties, by chemical oxidation with HNO(3) (AC(HNO3)) and O(2) (AC(O2)), and thermal treatments under H(2) (AC(H2)) or N(2) (AC(N2)) flow. The effect of modified AC on anaerobic chemical dye reduction was assayed with sulphide at different pH values 5, 7 and 9. Four dyes were tested: Acid Orange 7, Reactive Red 2, Mordant Yellow 10 and Direct Blue 71. Batch experiments with low amounts of AC (0.1 g L(-1)) demonstrated an increase of the first-order reduction rate constants, up to 9-fold, as compared with assays without AC. Optimum rates were obtained at pH 5 except for MY10, higher at pH 7. In general, rates increased with increasing the pH of point zero charge (pH(pzc)), following the trend AC(HNO3) < AC(O2) < AC(0) < AC(N2) < AC(H2). The highest reduction rate was obtained for MY10 with AC(H2) at pH 7, which corresponded to the double, as compared with non-modified AC. In a biological system using granular biomass, AC(H2) also duplicated and increase 4.5-fold the decolourisation rates of MY10 and RR2, respectively. In this last experiment, reaction rate was independent of AC concentration in the tested range 0.1-0.6 g L(-1). PMID:20800966

  12. Facile Preparation of Phosphotungstic Acid-Impregnated Yeast Hybrid Microspheres and Their Photocatalytic Performance for Decolorization of Azo Dye

    Directory of Open Access Journals (Sweden)

    Lan Chen

    2013-01-01

    Full Text Available Phosphotungstic acid (HPW-impregnated yeast hybrid microspheres were prepared by impregnation-adsorption technique through tuning pH of the aqueous yeast suspensions. The obtained products were characterized by field emission scanning electron microscopy (FE-SEM, energy dispersive spectrometry (EDS, X-ray diffraction (XRD, thermogravimetry-differential scanning calorimetry (TG-DSC, and ultraviolet-visible spectrophotometry (UV-Vis, respectively. FE-SEM and EDS ascertain that the HPW has been effectively introduced onto the surface of yeast, and the resulting samples retain ellipsoid shape, with the uniform size (length 4.5 ± 0.2 μm, width 3.0 ± 0.3 μm and good monodispersion. XRD pattern indicates that the main crystal structure of as-synthesized HPW@yeast microsphere is Keggin structure. TG-DTA states that the HPW in composites has better thermal stability than pure HPW. Fourier transform infrared spectroscopy (FT-IR elucidates that the functional groups or chemical bonds inherited from the pristine yeast cell were critical to the assembling of the composites. UV-Vis shows that the obtained samples have a good responding to UV light. The settling ability indicates that the hybrid microspheres possess an excellent suspension performance. In the test of catalytic activity, the HPW@yeast microsphere exhibits a high photocatalytic activity for the decoloration of Methylene blue and Congo red dye aqueous solutions, and there are a few activity losses after four cycles of uses.

  13. Evaluation of the adsorbent properties of a zeolite rock modified for the removal of the azo dyes as water pollutants; Evaluacion de las propiedades adsorbentes de una roca zeolitica modificada para la remocion de colorantes azoicos como contaminantes del agua

    Energy Technology Data Exchange (ETDEWEB)

    Torres P, J

    2005-07-01

    At the moment some investigations which make reference to the removal of dyes for diverse adsorbent materials; as well as the factors that influence in the sorption process, considering the type so much of dye as those characteristics of the adsorbent material. In this work were investigated those adsorbent properties of a zeolite rock coming from San Luis Potosi State for the removal of azo dyes, using as peculiar cases the Red 40 (Red Allura) and the Yellow 5 (Tartrazine); for it were determined kinetic parameters and the sorption isotherms, as well as the sorption mechanisms involved in each case, between the dyes and the zeolite rock. In this work also it was considered the characterization before and after to removal of color from the water, through advanced analytical techniques such as the scanning electron microscopy of high vacuum (SEM), elementary microanalysis (EDS) and X-ray diffraction (XRD). The experimental part of the work fundamentally consisted, in the conditioning with a NaCl solution and later on the modification with HDTMA-Br of the natural zeolite rock, for then to put it in contact with solutions of the dyes R-40 and A-5, varying so much the contact times as the concentrations; the quantification of sodium in the liquid phase after the modification of the zeolite rock to determine the capacity of external cation exchange (CICE) it was carried out by means of the atomic absorption spectroscopy technique (EAA), and the quantification of the surfactant and the dyes in the liquid phase, it was carried out by means of the UV-vis spectrophotometry technique. It was found that the kinetic model that better it describes the process of sorption of R-40 and A-5 for the modified zeolite rock with HDTMA-Br, leaving of monocomponent and bi component solutions, it is the pseudo- second order. Inside of the obtained results for the sorption isotherms, as much the dye R-40 as the dye A-5 its presented a better adjustment to the Langmuir model. In what refers

  14. Synthesis and characterization of novel liquid-crystalline azo-dyes bearing two amino-nitro substituted azobenzene units and a well-defined, oligo(ethylene glycol) spacer

    International Nuclear Information System (INIS)

    Highlights: → Novel dyes containing azobenzene and oligo(ethylene glycol) were synthesized. → Absorption spectra of RED-PEG dyes in CHCl3 showed λmax = 440-480 nm. → Absorption spectra of RED-PEG dyes in film revealed the formation of H-aggregates. → Their liquid-crystalline behaviour was confirmed by light polarized microscopy. → These liquid-crystalline dyes can form Langmuir films on the air-water interface. - Abstract: Four novel liquid-crystalline azo-dyes bearing two amino-nitro substituted azobenzene units linked by a well-defined oligo(ethylene glycol) spacer (DIRED-PEG series): (E)-N,N'-(2,2'-oxybis(ethane-2,1-diyl))bis(N-methyl-4-((E)-(4-nitrophenyl) diazenyl) benzenamine) (DIRED-PEG-2), (E)-N,N'-(2,2'-(ethane-1,2-diylbis(oxy)) bis(ethane-2,1-diyl)) bis(N-methyl-4-((E)-(4-nitrophenyl) diazenyl) benzenamine) (DIRED-PEG-3), (E)-N,N'-(2,2'-(2,2'-oxybis (ethane-2,1-diyl) bis(oxy)) bis(ethane-2,1-diyl)) bis(N-methyl-4-((E)-(4-nitrophenyl) diazenyl) benzenamine) (DIRED-PEG-4) and N1,N17-dimethyl-N1,N17-bis (4-((E)-(4-nitrophenyl) diazenyl) phenyl)-3,6,9,12,15-pentaoxaheptadecane-1,17-diamine (DIRED-PEG-6) have been synthesized. These dyes were fully characterized by FTIR, 1H and 13C NMR spectroscopies, and their thermal and optical properties were studied. Besides, the liquid-crystalline behaviour of these compounds was monitored in function of the temperature by light polarized microscopy. Finally, Langmuir films were prepared with these dyes.

  15. DECOLOURIZATION OF SELECTED PROCION DYE USING FUNGI, ACREMONIUM CHRYSOGENUM A COMPARISON WITH PHYSICAL ADSORBENTS

    OpenAIRE

    M. Prasad Naidu; Aruna, P

    2015-01-01

    Azo dyes, based on aromatic amines, may contain these amines as impurities introduced during the manufacturing process. Aromatic amines may also be present as a result of thermal or photochemical degradation of azo dyes. The more stable derivatives contain two aryl groups. As a consequence of ?-delocalization, aryl azo compounds have vivid colors, especially reds, oranges, and yellows. Therefore, they are used as dyes, and are commonly known as azo dyes, an example of which is Disperse Orange...

  16. Monoazo and diazo dye decolourisation studies in a methanogenic UASB reactor

    OpenAIRE

    Gomes, Arlindo Caniço; Gonçalves, Isolina Cabral; Pinheiro, H. M.; Ferra, M .I. A.

    2010-01-01

    Mixed anaerobic bacterial consortia have been show to reduce azo dyes and batch decolourisation tests have also demonstratedthat predominantly methanogenic cultures also perform azo bond cleavage. The anaerobic treatment of wool dyeing effluents, which contain acetic acid, could thus be improved with a better knowledge of methanogenic dye degradation. Therefore, the decolourisation of two azo textile dyes, a monoazo dye (Acid Orange 7, AO7) and a diazo dye (Direct Red 254, DR254), was investi...

  17. Influence of ionic strength in the adsorption and during photocatalysis of reactive black 5 azo dye on TiO{sub 2} coated on non woven paper with SiO{sub 2} as a binder

    Energy Technology Data Exchange (ETDEWEB)

    Aguedach, Abdelkahhar [Laboratoire de l' Eau et environnement, Universite Chouaib Doukkali, Faculte des Sciences, BP.20, El Jadida, Maroc (Morocco); Brosillon, Stephan [Laboratoire Science Chimiques de Rennes UMR 6226, Equipe Chimie et Ingenierie des Procedes, Ecole Nationale Superieure de Chimie, Universite Rennes 1, avenue du General Leclerc, 35700 Rennes (France)], E-mail: Stephan.Brosillon@ensc-rennes.fr; Morvan, Jean [Laboratoire Science Chimiques de Rennes UMR 6226, Equipe Chimie et Ingenierie des Procedes, Ecole Nationale Superieure de Chimie, Universite Rennes 1, avenue du General Leclerc, 35700 Rennes (France); Lhadi, El Kbir [Laboratoire de l' Eau et environnement, Universite Chouaib Doukkali, Faculte des Sciences, BP.20, El Jadida, Maroc (Morocco)

    2008-01-31

    Reactive black 5 (RB5), an azo dye, was degraded by using UV-irradiated TiO{sub 2} coated on non woven paper with SiO{sub 2} as a binder. The adsorption capacity of the photocatalyst was studied at natural pH, superior to pH{sub pzc} of the binder, for various ionic strengths. Different salts such as NaCl, KCl, CaCl{sub 2}, LiCl, Ca(NO{sub 3}){sub 2} were used to increase the ionic strength. The presence of salt increased the adsorption capacity. The electrostatic interactions between dye and oxide surface charges (TiO{sub 2}/SiO{sub 2}) is very important in the adsorption phenomena. The effect of the ionic strength of the solution on photocatalyst degradation was studied. The rate of degradation was increased by the presence of salts in the range of the experimental conditions. The increase of the initial decolorization rate was observed in the following order: Ca{sup 2+} > K{sup +} > Na{sup +} > Li{sup +}. Experiments with different anions (Cl{sup -}, NO{sub 3}{sup -}) had shown that nitrate was an indifferent electrolyte for the adsorption and photodegradation of the dye on SiO{sub 2}/TiO{sub 2}.

  18. Influence of ionic strength in the adsorption and during photocatalysis of reactive black 5 azo dye on TiO2 coated on non woven paper with SiO2 as a binder

    International Nuclear Information System (INIS)

    Reactive black 5 (RB5), an azo dye, was degraded by using UV-irradiated TiO2 coated on non woven paper with SiO2 as a binder. The adsorption capacity of the photocatalyst was studied at natural pH, superior to pHpzc of the binder, for various ionic strengths. Different salts such as NaCl, KCl, CaCl2, LiCl, Ca(NO3)2 were used to increase the ionic strength. The presence of salt increased the adsorption capacity. The electrostatic interactions between dye and oxide surface charges (TiO2/SiO2) is very important in the adsorption phenomena. The effect of the ionic strength of the solution on photocatalyst degradation was studied. The rate of degradation was increased by the presence of salts in the range of the experimental conditions. The increase of the initial decolorization rate was observed in the following order: Ca2+ > K+ > Na+ > Li+. Experiments with different anions (Cl-, NO3-) had shown that nitrate was an indifferent electrolyte for the adsorption and photodegradation of the dye on SiO2/TiO2

  19. A novel ammonia-assisted method for the direct synthesis of Mn3O4 nanoparticles at room temperature and their catalytic activity during the rapid degradation of azo dyes

    Science.gov (United States)

    Mansournia, Mohammadreza; Azizi, Fatemeh; Rakhshan, Narges

    2015-05-01

    In this study, we prepared trimanganese tetroxide nanoparticles from MnCl2 solution in an ammonia atmosphere using a new surfactant-free method at room temperature. We analyzed and characterized the effects of different processing conditions, such as the concentrations of manganese and the ammonia source, as well as the reaction time, on the structure, purity, and morphology of the products using powder X-ray diffraction (XRD), scanning electron microscopy, and Fourier transformation infrared spectroscopy (FTIR) techniques. The XRD and FTIR analyses confirmed that the prepared products comprised single phase Mn3O4. At room temperature, the paramagnetic characteristics were also verified by vibrating sample magnetometry. Furthermore, we tested the catalytic activity of the nanoparticles during the degradation of methyl orange and Congo red, which are organic pollutants. Our experiments demonstrated the rapid color removal and reduction in the chemical oxygen demand (>70% and >50% within 10 min, respectively) using aqueous solutions of azo dyes.

  20. Assessment of toxicity and genotoxicity of the reactive azo dyes Remazol Black B and Remazol Orange 3R and effectiveness of electron beam irradiation in the reduction of color and toxic effects; Avaliacao da toxicidade e genotoxicidade dos corantes azo reativos Remazol Preto B e Remazol Alaranjado 3R e da eficacia da radiacao com feixe de eletrons na reducao da cor e efeitos toxicos

    Energy Technology Data Exchange (ETDEWEB)

    Pinheiro, Alessandro de Sa

    2011-07-01

    The textile industries play an important role in national and global economy. But, their activities are considered potentially polluting. The use of large volumes of water and the production of colored wastewater with high organic matter are among the main issues raised, especially during the stage of dyeing and washing of the textile process. The reactive azo dyes are the main colors used in the industry for dyeing of cotton in Brazil and worldwide. Because of its low setting and variations in the fiber production process, about 30% of the initial concentration used in the dyeing baths are lost and will compose the final effluent. These compounds have a low biodegradability, are highly soluble in water and therefore are not completely removed by conventional biological processes. In addition, other processes do not promote degradation but the transference to solid environment. The dyes discarded without treatment in the water body can cause aesthetic modifications, alter photosynthesis and gas solubility, as well as being toxic and genotoxic. The main objectives of this study were to evaluate the toxicity and genotoxicity of two reactive azo dyes (Remazol Black B - RPB and Remazol Orange 3R - R3AR) and the percentage of color and toxicity reduction after the use of electron beam radiation. The acute toxicity assays performed with Vibrio fischeri, Daphnia similis and Biomphalaria glabrata showed different response patterns for dyes. The different chemical forms of dyes were slightly toxic to Vibrio fischeri and only the RPB dye (vinylsulphone) was toxic (EC50{sub 15min} = 6,23 mg L-1). In tests with Daphnia similis, the dye RPB was slightly toxic in its pattern form, sulphatoethylsulphone, (CE50{sub 48h} = 91,25 mg L{sup -1}) and showed no toxicity in other chemical forms. However, the RA3R dye was toxic to the dafnids and the vinylsulphone form very toxic (EC50{sub 48h} = 0,54 mg L-1). No toxicity was observed in Biomphalaria glabrata assays. Chronic toxicity was

  1. DECOLORIZATION OF AZO DYES WITH DIFFERENT MOLECULAR STRUCTURE BY Enterobactor sp.S8%菌株Enterobactor sp.S8对不同结构偶氮染料脱色性能的影响

    Institute of Scientific and Technical Information of China (English)

    陈晔; 陈刚; 陈亮; 黄满红

    2011-01-01

    采用一种具有广谱性的高效脱色菌Enterobactor sp.S8对16种不同结构的偶氮染料进行厌氧脱色研究,并将菌株对偶氮染料的吸附脱色和降解脱色两种作用分离开来研究,考察偶氮染料分子中与偶氮键直接相连的芳环上取代基种类对染料降解脱色作用的影响规律.结果表明,菌株Enterobactor sp.S8对活性染料的脱色作用以降解为主,对分散染料则以吸附为主.染料分子中芳环上-OCH3取代阻碍菌株对染料的脱色,-Cl取代对染料的降解脱色作用无较大影响,-NHCOCH3和-SO3H取代可促进染料的降解脱色作用,-SO3H取代比-COOH取代易于使染料脱色,染料分子中杂环和金属离子的存在使染料毒性增大,从而阻碍脱色作用.%The effect of efficient broad-spectrum strain Enterobacter sp. S8 on the decolorization of 16 azo dyes with different molecular structure under anaerobic condition was studied. Adsorption and degradation were studied separately in order to explore the effect of substituent species on the aromatic ring on degradation decolorization. The results showed that reactive dyes were decolorized mainly by degradation, while disperse dyes mainly attributed to adsorption by bacterial. —OCH3 substitution on aromatic ring hindered decolorization. -Cl substitution had no effect on degradation. Both —NHCOCH3 and —SO3 H substitutent promoted degradation, and —SO3 H substituted dyes were more easily decolorized than —COOH substituted dyes. Moreover, the heterocyclic and metal ions contained in the dye structure enhanced the toxicity of dyes and hindered their decolorization.

  2. Ozo-Dyes mixture degradation in a fixed bed biofilm reactor packed with volcanic porous rock

    International Nuclear Information System (INIS)

    Textile industries discharge great amounts of dyes and dyeing-process auxiliaries, which pollute streams and water bodies. Several dyes, especially the ones containing the azo group, can cause harmful effects to different organisms including humans. Through bacterial and mammalian tests, azo dyes or their derived aromatic amines have shown cell genotoxicity. The purpose of this work was to evaluate the effect of air flow rate on azo-dyes mixture biodegradation by a microbial community immobilized in a packed bed reactor. (Author)

  3. Ozo-Dyes mixture degradation in a fixed bed biofilm reactor packed with volcanic porous rock

    Energy Technology Data Exchange (ETDEWEB)

    Contreras-Blancas, E.; Cobos-Vasconcelos, D. de los; Juarez-Ramirez, C.; Poggi-Varaldo, H. M.; Ruiz-Ordaz, N.; Galindez-Mayer, J.

    2009-07-01

    Textile industries discharge great amounts of dyes and dyeing-process auxiliaries, which pollute streams and water bodies. Several dyes, especially the ones containing the azo group, can cause harmful effects to different organisms including humans. Through bacterial and mammalian tests, azo dyes or their derived aromatic amines have shown cell genotoxicity. The purpose of this work was to evaluate the effect of air flow rate on azo-dyes mixture biodegradation by a microbial community immobilized in a packed bed reactor. (Author)

  4. Degradation of the azo dye Acid Red 1 by anodic oxidation and indirect electrochemical processes based on Fenton's reaction chemistry. Relationship between decolorization, mineralization and products

    International Nuclear Information System (INIS)

    Highlights: • Degradation of Acid Red 1 by anodic oxidation, electro-Fenton and photoelectro-Fenton • Quicker and similar decolorization by electro-Fenton and photoelectro-Fenton due to oxidation with ●OH in the bulk • Almost total mineralization by photoelectro-Fenton with Pt or BDD due to fast photolysis of products by UVA light • Detection of 11 aromatic products, 15 hydroxylated compounds, 13 desulfonated derivatives and 7 carboxylic acids • Release of NH4+, NO3− and SO42− ions, and generation of persistent N-products of low molecular mass - Abstract: Solutions of 236 mg dm−3 Acid Red 1 (AR1), an azo dye widely used in textile dying industries, at pH 3.0 have been comparatively treated by anodic oxidation with electrogenerated H2O2 (AO-H2O2), electro-Fenton (EF) and photoelectro-Fenton (PEF) at constant current density (j). Assays were performed with a stirred tank reactor equipped with a Pt or boron-doped diamond (BDD) anode and an air-diffusion cathode for H2O2 generation from O2 reduction. The main oxidizing agents were hydroxyl radicals produced at the anode from water oxidation in all methods and in the bulk from Fenton's reaction between generated H2O2 and 0.5 mmol dm−3 Fe2+ in EF and PEF. For each anode, higher oxidation power was found in the sequence AO-H2O2 < EF < PEF. The oxidation ability of the BDD anode was always superior to that of Pt. Faster and similar decolorization efficiency was achieved in EF and PEF owing to the quicker destruction of aromatics with hydroxyl radicals produced in the bulk. The PEF process with BDD was the most potent method yielding almost total mineralization due to the additional rapid photolysis of recalcitrant intermediates like Fe(III)-carboxylate complexes under UVA irradiation. The increase in j always enhanced the decolorization and mineralization processes because of the greater production of hydroxyl radicals, but decreases the mineralization current efficiency. A total of 11 aromatic

  5. Comparative studies of operational parameters of degradation of azo dyes in visible light by highly efficient WOx/TiO2 photocatalyst.

    Science.gov (United States)

    Sajjad, Ahmed Khan Leghari; Shamaila, Sajjad; Tian, Baozhu; Chen, Feng; Zhang, Jinlong

    2010-05-15

    The multidimensional aspects of the photocatalytic activity were investigated in a systematic way by employing the dyes Acid Orange 7 (AO7) and Methyl Orange (MO) as substrates in terms of their degradation or conversion rates. 4.0% WO(x)/TiO(2) nanocomposite demonstrated the best reactivity under visible light, allowing more efficient usage of solar light. The reduced form of W decreased the band gap and inhibited electron hole recombination efficiently. This composite was characterized by X-ray diffraction spectroscopy (XRD), UV-vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). A series of experiments were conducted to investigate the operational parameters under visible light irradiation such as optimization of nanocomposites wt%, change of pH, reuse of catalyst and initial dye concentration. The kinetics of the dyes degradation was found to follow the Langmuir-Hinshelwood model. Decomposition or mineralization was investigated with the changes of absorption spectra, pH, degradation efficiency and TOC removal in visible irradiation systems. FT-IR spectroscopy of these adsorbed dyes on WO(x)/TiO(2) powder provided an insight to the mode of its adsorption on WO(x)/TiO(2). It was found that the dye adsorbed on WO(x)/TiO(2) underwent a series of oxidation steps which lead to decolorization and formation of a number of intermediates mainly aromatic and aliphatic acids. These intermediates were quantified by GC/GC-MS. PMID:20074854

  6. Comparative studies of operational parameters of degradation of azo dyes in visible light by highly efficient WOx/TiO2 photocatalyst

    International Nuclear Information System (INIS)

    The multidimensional aspects of the photocatalytic activity were investigated in a systematic way by employing the dyes Acid Orange 7 (AO7) and Methyl Orange (MO) as substrates in terms of their degradation or conversion rates. 4.0% WOx/TiO2 nanocomposite demonstrated the best reactivity under visible light, allowing more efficient usage of solar light. The reduced form of W decreased the band gap and inhibited electron hole recombination efficiently. This composite was characterized by X-ray diffraction spectroscopy (XRD), UV-vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). A series of experiments were conducted to investigate the operational parameters under visible light irradiation such as optimization of nanocomposites wt%, change of pH, reuse of catalyst and initial dye concentration. The kinetics of the dyes degradation was found to follow the Langmuir-Hinshelwood model. Decomposition or mineralization was investigated with the changes of absorption spectra, pH, degradation efficiency and TOC removal in visible irradiation systems. FT-IR spectroscopy of these adsorbed dyes on WOx/TiO2 powder provided an insight to the mode of its adsorption on WOx/TiO2. It was found that the dye adsorbed on WOx/TiO2 underwent a series of oxidation steps which lead to decolorization and formation of a number of intermediates mainly aromatic and aliphatic acids. These intermediates were quantified by GC/GC-MS.

  7. Gamma irradiation of natural dyes

    International Nuclear Information System (INIS)

    Dyes play an important role in textile industry. Synthetic dyes of various classes are normally used for dyeing fabrics. Recently, considerable attention is focussed on the use of natural dyes all over the world in the context of German ban on some of synthetic azo dye due to their allergenic or carcinogenic potential. However natural dyes and their solution in aqueous medium show microbial contamination on storage. The present study deals with effect of gamma radiation on the microbial load, tinctorial value and dye uptake of natural dyes. (author)

  8. Effect of ferromagnetic nanoparticle on dyes biodegradation

    OpenAIRE

    Apostol, Laura; Pereira, Luciana; Pereira, Raquel; Alves, M. M.; Gavrilescu, M

    2011-01-01

    In this study the biodecolourisation of two dyes, a xanthene dye, Erythrosine B (Ery B) and an azo dye, Reactive Red 51 (RR120), was investigated colourdecolourisationunder batch anaerobic conditions by using non - acclimated anaerobic granular sludge. The effect of ferromagnetic nanoparticle (FN) (as adsorbent or mediator) on dyes removal was experienced.

  9. Comparative studies of operational parameters of degradation of azo dyes in visible light by highly efficient WO{sub x}/TiO{sub 2} photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Sajjad, Ahmed Khan Leghari; Shamaila, Sajjad; Tian Baozhu; Chen Feng [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Zhang Jinlong, E-mail: jlzhang@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); School of Chemistry and Materials Science, Guizhou Normal University, Guiyang 550001 (China)

    2010-05-15

    The multidimensional aspects of the photocatalytic activity were investigated in a systematic way by employing the dyes Acid Orange 7 (AO7) and Methyl Orange (MO) as substrates in terms of their degradation or conversion rates. 4.0% WO{sub x}/TiO{sub 2} nanocomposite demonstrated the best reactivity under visible light, allowing more efficient usage of solar light. The reduced form of W decreased the band gap and inhibited electron hole recombination efficiently. This composite was characterized by X-ray diffraction spectroscopy (XRD), UV-vis diffuse reflectance spectroscopy (DRS), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX). A series of experiments were conducted to investigate the operational parameters under visible light irradiation such as optimization of nanocomposites wt%, change of pH, reuse of catalyst and initial dye concentration. The kinetics of the dyes degradation was found to follow the Langmuir-Hinshelwood model. Decomposition or mineralization was investigated with the changes of absorption spectra, pH, degradation efficiency and TOC removal in visible irradiation systems. FT-IR spectroscopy of these adsorbed dyes on WO{sub x}/TiO{sub 2} powder provided an insight to the mode of its adsorption on WO{sub x}/TiO{sub 2}. It was found that the dye adsorbed on WO{sub x}/TiO{sub 2} underwent a series of oxidation steps which lead to decolorization and formation of a number of intermediates mainly aromatic and aliphatic acids. These intermediates were quantified by GC/GC-MS.

  10. Synthesis of magnetically recyclable MnFe2O4@SiO2@Ag nanocatalyst: Its high catalytic performances for azo dyes and nitro compounds reduction

    Science.gov (United States)

    Kurtan, U.; Amir, Md.; Yıldız, A.; Baykal, A.

    2016-07-01

    In this study, magnetically recycable MnFe2O4@SiO2@Ag nanocatalyst (MnFe2O4@SiO2@Ag MRCs) has been synthesized through co-precipition and chemical reduction method. XRD analysis confirmed the synthesis of single phase nanoproduct with crystallite size of 10 nm. VSM measurements showed the superparamagnetic property of the product. Catalytic studies showed that MnFe2O4@SiO2@Ag MRC could catalyze the reduction of the various azo compounds like methyl orange (MO), methylene blue (MB), eosin Y (EY), and rhodamine B (RhB) and also aromatic nitro compounds such as 4-nitrophenol (4-NP), 4-nitroaniline (4-NA) and 2-nitroaniline (2-NA). Moreover, the magnetic nanocatalyst showed an excellent reusability properties that remained unchanged after several cycles. Therefore, MnFe2O4@SiO2@Ag is the potential candidate for the application of organic pollutants for wastewater treatment.

  11. Treatment of azo dye-containing wastewater by a Fenton-like process in a continuous packed-bed reactor filled with activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Mesquita, Isabel; Matos, Luis C. [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Duarte, Filipa [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal); Maldonado-Hodar, F.J. [Department of Inorganic Chemistry, Faculty of Sciences, University of Granada, Av. Fuentenueva, 18071 Granada (Spain); Mendes, Adelio [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal); Madeira, Luis M., E-mail: mmadeira@fe.up.pt [Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); LEPAE - Laboratory for Process, Environmental and Energy Engineering, Department of Chemical Engineering, Faculty of Engineering, University of Porto, Porto (Portugal)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Oxidation with the Fenton's reagent was carried out in a packed-bed reactor. Black-Right-Pointing-Pointer The packed-bed was filled with iron-impregnated activated carbon. Black-Right-Pointing-Pointer The increment of temperature increases the Chicago Sky Blue removal and mineralization. Black-Right-Pointing-Pointer The values of iron leaching were below 0.4 ppm in the outlet effluent. Black-Right-Pointing-Pointer It was possible to reach a dye conversion of 88% in steady-state. - Abstract: In this work, oxidation with a Fenton-like process of a dye solution was carried out in a packed-bed reactor. Activated carbon Norit RX 3 Extra was impregnated with ferrous sulfate and used as catalyst (7 wt.% of iron). The effect of the main operating conditions in the Chicago Sky Blue (CSB) degradation was analyzed. It was found that the increase in temperature leads to a higher removal of the dye and an increased mineralization. However, it also increases the iron leaching, but the values observed were below 0.4 ppm (thus, far below European Union limits). It was possible to reach, at steady-state, a dye conversion of 88%, with a total organic carbon (TOC) removal of ca. 47%, being the reactor operated at 50 Degree-Sign C, pH 3, W{sub cat}/Q = 4.1 g min mL{sup -1} (W{sub cat} is the mass of catalyst and Q the total feed flow rate) and a H{sub 2}O{sub 2} feed concentration of 2.25 mM (for a CSB feed concentration of 0.012 mM). The same performance was reached in three consecutive cycles.

  12. Treatment of azo dye-containing wastewater by a Fenton-like process in a continuous packed-bed reactor filled with activated carbon

    International Nuclear Information System (INIS)

    Highlights: ► Oxidation with the Fenton's reagent was carried out in a packed-bed reactor. ► The packed-bed was filled with iron-impregnated activated carbon. ► The increment of temperature increases the Chicago Sky Blue removal and mineralization. ► The values of iron leaching were below 0.4 ppm in the outlet effluent. ► It was possible to reach a dye conversion of 88% in steady-state. - Abstract: In this work, oxidation with a Fenton-like process of a dye solution was carried out in a packed-bed reactor. Activated carbon Norit RX 3 Extra was impregnated with ferrous sulfate and used as catalyst (7 wt.% of iron). The effect of the main operating conditions in the Chicago Sky Blue (CSB) degradation was analyzed. It was found that the increase in temperature leads to a higher removal of the dye and an increased mineralization. However, it also increases the iron leaching, but the values observed were below 0.4 ppm (thus, far below European Union limits). It was possible to reach, at steady-state, a dye conversion of 88%, with a total organic carbon (TOC) removal of ca. 47%, being the reactor operated at 50 °C, pH 3, Wcat/Q = 4.1 g min mL−1 (Wcat is the mass of catalyst and Q the total feed flow rate) and a H2O2 feed concentration of 2.25 mM (for a CSB feed concentration of 0.012 mM). The same performance was reached in three consecutive cycles.

  13. A comparative study on decolorization of reactive azo and indigoid dyes by free/immobilized pellets of Trametes versicolor and Funalia trogii.

    Science.gov (United States)

    Yildirim, Seval Cing; Yesilada, Ozfer

    2015-11-01

    The objective of the present study was to investigate decolorization of Acid Blue 74 and Reactive Blue 198 dyes by free and immobilized white rot fungal pellets in order to confirm the possibility of practical application via repeated-batch cultivation. Decolorization studies were conducted using free pellets (FP), fungal cells immobilized on activated carbon (IFCAC) and pinewood (IFCP), and also fungal cells entrapped in alginate beads (FCEAB). No additional nitrogen and carbon source was used and high decolorization rates were achieved in only dye-contained media without pH adjustment. Acid Blue 74 was decolorized 96 and 94% within 2 hr by Trametes versicolor and Funalia trogii free pellets, respectively. These values were 87 and 84% for Reactive Blue 198, in this respect. Immobilization of fungal cells on pinewood increased the usability of pellets and the average decolorization efficiency of both dyes. The micro environment changed in the presence of pinewood and increased the stability of immobilized pellets. Decolorization was performed rapidly and efficiently. Laccase activity enhanced with availability of pinewood, and high laccase production with F. trogii was obtained. After separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), the molecular weight of T versicolor and F. trogii laccase bands was determined 64 and 61 kDa approximately. Green bands were obtained by the activity staining process with laccase substrate (ABTS) after gel renaturation step. PMID:26688979

  14. Fabrication of nanospinel ZnCr2O4 using sol-gel method and its application on removal of azo dye from aqueous solution

    International Nuclear Information System (INIS)

    For the first time, nanoparticles of zinc chromite, spinel ZnCr2O4 have been fabricated by the thermal decomposition of Zn-Cr gel prepared by sol-gel method in the presence of oxalic acid as a chelating agent. It was shown that the well-crystallized spinel structure is formed after calcination at 450 deg. C. The nanospinel has been characterized by differential thermal analysis (DTA), X-ray powder diffraction (XRD), infrared spectroscopy (IR), and transmission electron microscope (TEM). The average particle size is approximately 13 nm according to the TEM image. The nanoparticles of zinc chromites showed excellent adsorption properties towards reactive dye, reactive blue 5 (RB5). The adsorption studies have been carried out for contact time, different pH values, different temperatures, and adsorbent doses. The investigation of removal kinetics of RB5 indicates that the removal process obeys the rate of second-order kinetic equation. The results indicate that the Langmuir adsorption isotherm fitted the data better than the Freundlich. Also, the photocatalytic degradation of RB5 using spinel ZnCr2O4 under UV irradiation at pH = 1 has been also examined. The results showed that the degradation of RB5 dye follows merely an adsorption process.

  15. Fabrication of nanospinel ZnCr2O4 using sol-gel method and its application on removal of azo dye from aqueous solution.

    Science.gov (United States)

    Yazdanbakhsh, Mohammad; Khosravi, Iman; Goharshadi, Elaheh K; Youssefi, Abbas

    2010-12-15

    For the first time, nanoparticles of zinc chromite, spinel ZnCr(2)O(4) have been fabricated by the thermal decomposition of Zn-Cr gel prepared by sol-gel method in the presence of oxalic acid as a chelating agent. It was shown that the well-crystallized spinel structure is formed after calcination at 450°C. The nanospinel has been characterized by differential thermal analysis (DTA), X-ray powder diffraction (XRD), infrared spectroscopy (IR), and transmission electron microscope (TEM). The average particle size is approximately 13 nm according to the TEM image. The nanoparticles of zinc chromites showed excellent adsorption properties towards reactive dye, reactive blue 5 (RB5). The adsorption studies have been carried out for contact time, different pH values, different temperatures, and adsorbent doses. The investigation of removal kinetics of RB5 indicates that the removal process obeys the rate of second-order kinetic equation. The results indicate that the Langmuir adsorption isotherm fitted the data better than the Freundlich. Also, the photocatalytic degradation of RB5 using spinel ZnCr(2)O(4) under UV irradiation at pH=1 has been also examined. The results showed that the degradation of RB5 dye follows merely an adsorption process. PMID:20863619

  16. Isolation, development and identification of salt-tolerant bacterial consortium from crude-oil-contaminated soil for degradation of di-azo dye Reactive Blue 220.

    Science.gov (United States)

    Patel, Vipul R; Bhatt, Nikhil

    2015-01-01

    The objective of this study was development and characterization of a halophilic bacterial consortium for rapid decolorization and degradation of a wide range of dyes and their mixtures. The 16S rRNA gene analysis of developed halophilic consortium VN.1 showed that the bacterial consortium contained six bacterial strains, which were identified as Pseudomonas fluorescens HM480360, Enterobacter aerogenes HM480361, Shewanella sp. HM589853, Arthrobacter nicotianae HM480363, Bacillus beijingensis HM480362 and Pseudomonas aeruginosa JQ659549. Halophilic consortium VN.1 was able to decolorize up to 2,500 mg/L RB220 with >85% chemical oxygen demand (COD) reduction under static condition at 30 °C and pH 8.0 in the presence of 7% NaCl. VN.1 also exhibited more than 85% COD reduction with >25 mg/(L h) rate of decolorization in the case of different reactive dye mixtures. We propose the symmetric cleavage of RB220 using Fourier transform infrared, high-performance liquid chromatography (HPLC), nuclear magnetic resonance and gas chromatography-mass spectrometry analysis, and confirmed the formation of sodium-4-aminobenzenesulfonate, sodium-6-aminonepthalenesulfonate, and sodiumbenzene/nepthalenesulfonate. Toxicity studies confirm that the biodegraded products of RB220 effluent stimulate the growth of plants as well as the bacterial community responsible for soil fertility. PMID:26177415

  17. Magnetic Mn substituted cobalt zinc ferrite systems: Structural, electrical and magnetic properties and their role in photo-catalytic degradation of methyl orange azo dye

    Energy Technology Data Exchange (ETDEWEB)

    Bhukal, Santosh [Department of Environment Studies, Panjab University, Chandigarh 160014 (India); Bansal, S. [DST, New Delhi (India); Singhal, Sonal, E-mail: sonal1174@gmail.com [Department of Chemistry, Panjab University, Chandigarh 160014 (India)

    2014-07-15

    The present work focuses on the effect of replacement of Fe{sup 3+} ions by the Mn{sup 3+} ions in cobalt zinc ferrites (Co{sub 0.6}Zn{sub 0.4}Mn{sub x}Fe{sub 2−x}O{sub 4} (0.2, 0.4, 0.6, 0.8 and 1.0) on the structural, magnetic, electrical and catalytic properties. Powder X-ray diffraction studies confirmed that all the samples possessed cubic spinel structure with Fd-3m space groups. The saturation magnetization was found to decrease with increase in Mn{sup 3+} ions concentration. The drift mobility of all compositions was found to decrease with increase in temperature which could be attributed to the semiconductor nature of nanoferrites. The photo-catalytic activity of all the nanoferrites was evaluated by the degradation of methyl orange dye and it was observed that the degradation of methyl orange dye was enhanced with increase in Mn{sup 3+} ions concentration from 0.2 to 1.0. This might be due to the octahedral site preference and higher redox potential of manganese ion as compared those of iron.

  18. Rapid degradation of azo dye Direct Black BN by magnetic MgFe2O4-SiC under microwave radiation

    Science.gov (United States)

    Gao, Jia; Yang, Shaogui; Li, Na; Meng, Lingjun; Wang, Fei; He, Huan; Sun, Cheng

    2016-08-01

    A novel microwave (MW) catalyst, MgFe2O4 loaded on SiC (MgFe2O4-SiC), was successfully synthesized by sol-gel method, and pure MgFe2O4 was used as reference. The MgFe2O4 and MgFe2O4-SiC catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), N2 adsorption analyzer (BET specific surface area), X-ray photoelectron spectroscopy (XPS). The electromagnetic parameters of the prepared catalysts were measured by vector network analyzer. The reflection loss (RL) based on the electromagnetic parameters calculated in Matlab showed MgFe2O4-SiC attained the maximum absorbing value of 13.32 dB at 2.57 GHz, which reached extremely high RL value at low frequency range, revealing the excellent MW absorption property of MgFe2O4-SiC. MW-induced degradation of Direct Black BN (DB BN) over as-synthesized MgFe2O4-SiC indicated that degradation efficiency of DB BN (20 mg L-1) in 5 min reached 96.5%, the corresponding TOC removal was 65%, and the toxicity of DB BN after degradation by MgFe2O4-SiC obviously decreased. The good stability and applicability of MgFe2O4-SiC on the degradation process were also discovered. Moreover, the ionic chromatogram during degradation of DB BN demonstrated that the C-S, C-N and azo bonds in the DB BN molecule were destroyed gradually. MW-induced rad OH and holes could be responsible for the efficient removal involved in the system. These findings make MgFe2O4-SiC become an excellent MW absorbent as well as an effective MW catalyst with rapid degradation of DB BN. Therefore, it may be promising for MgFe2O4-SiC under MW radiation to deal with various dyestuffs and other toxic organic pollutants.

  19. Comparative study of the pretreatment of azo printing and dyeing wastewater%偶氮染料印染废水预处理方法的比较研究

    Institute of Scientific and Technical Information of China (English)

    孙竹梅; 吴翔; 方炯; 杜冬云

    2013-01-01

    The alkaline wastewater,mainly azo dyes,in a plant in Hubei Province,is characterized by poor biodegra-dability,high chroma,and high COD. In order to solve these problems,some pretreatment methods,such as coagulation, Fenton reagent,and ozone oxidation have been used. The results show that among the three methods,the pretreatment efficiency of ozone oxidation method is the best, but its treatment cost is too high. When ferrous sulphate and poly-ferrous sulphate are used complexly,with 100 mL dyeing and printing wastewater,the dosages of ferrous sulphate is 0.05 g and 8% of poly-ferrous sulphate 1.00 mL,the COD removing rate reaches 49.35%,chroma removing rate 87.50%, B/C is increased to 0.34, the efficacy is next to the best. The efficacy by using Fenton reagent is the worst. Taking all factors into consideration, the pretreatment method which is suitable for this wastewater is the coagulation which uses ferrous sulphate and poly-ferrous sulphate complexly.%为解决湖北某厂以偶氮染料为主的碱性印染废水可生化性差、色度高、COD高等问题,采用絮凝、Fenton试剂和臭氧氧化的预处理方法对其进行处理,比较了3种方法的处理效果.结果表明:3种方法中,臭氧氧化预处理效果最好,但处理成本太高;硫酸亚铁和聚合硫酸铁复合使用时,于100 mL印染废水中投加0.05 g硫酸亚铁和1.00 mL 8%聚合硫酸铁,COD去除率达49.35%,色度去除率为87.50%,B/C升高至0.34,效果次之;Fenton试剂预处理,效果最差.综合考虑,适合此废水的预处理方法为硫酸亚铁和聚合硫酸铁复合使用的絮凝法.

  20. 40 CFR 721.2577 - Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine...

    Science.gov (United States)

    2010-07-01

    ... sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt (generic). 721.2577 Section 721.2577... Copper complex of (substituted sulfonaphthyl azo substituted phenyl) disulfonaphthyl azo, amine salt... substances identified generically as copper complex of (substituted sulfonaphthyl azo substituted...

  1. Enhanced photocatalytic efficiency of NiS/TiO{sub 2} composite catalysts using sunset yellow, an azo dye under day light illumination

    Energy Technology Data Exchange (ETDEWEB)

    Rajamanickam, D.; Dhatshanamurthi, P.; Shanthi, M., E-mail: shanthimsm@gmail.com

    2015-01-15

    Highlights: • NiS/TiO{sub 2} was successfully synthesized by sol–gel method. • This new method of preparation gives a homogeneous dispersion of NiS on TiO{sub 2}. • Degradation activity of NiS/TiO{sub 2} is found to be more efficient than other catalysts. • Addition of oxidants enhances the degradation efficiency significantly. • COD measurements reveal the complete mineralization of dye molecules. • The catalyst is found to be reusable. - Abstract: To improve the solar light induced photocatalytic application performances of TiO{sub 2}, in this study, the NiS modified TiO{sub 2} composite photocatalysts with various ratios of NiS to TiO{sub 2} were prepared by sol–gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller (B–E–T) surface area measurement methods. The photocatalytic activity of NiS/TiO{sub 2} was investigated for the degradation of sunset yellow (SY) in aqueous solution using solar light. The NiS/TiO{sub 2} is found to be more efficient than prepared TiO{sub 2} and TiO{sub 2}–P25 at pH 7 for the mineralization of SY. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The degradation was strongly enhanced in the presence of oxidants such as H{sub 3}K{sub 5}O{sub 18}S{sub 4} (Oxone), KIO{sub 4}, and KBrO{sub 3}. The mineralization of SY has been identified by COD measurements. The catalyst is found to be reusable.

  2. Delaminated montmorillonite with iron(III)-TiO2 species as a photocatalyst for removal of a textile azo-dye from aqueous solution.

    Science.gov (United States)

    Torres-Luna, Juan A; Carriazo, José G; Sanabria, Nancy R

    2016-06-01

    A set of mesoporous delaminated montmorillonites containing iron(III)-titanium oxide species was synthesized using two minerals: a bentonite as support and an ilmenite as source of Fe-TiO2 species. Several values of both sulphuric acid concentration and temperature were employed to extract Fe-TiO2 species from an ilmenite. Analyses by X-ray fluorescence, X-ray diffraction, scanning electron microscopy and nitrogen adsorption-desorption confirmed the successful formation of delaminated (or exfoliated) mesoporous structures. Optical properties of solids were determined by UV-Vis diffuse reflectance spectroscopy, and their band gap energy values were also calculated. A small UV-shift of band gap values regarding that of commercial photo-active TiO2 was detected as consequence of the quantum size effect, suggesting that photocatalytic experiments should be performed under UV-radiation assistance. The synthesized solids showed good activity in the photocatalytic oxidation of a textile dye (reactive yellow 145: RY 145), achieving conversions higher than 70% and chemical oxygen demand removal between 60% and 80%. PMID:26586178

  3. Photocatalytic degradation of an azo dye Sunset Yellow under UV-A light using TiO2/CAC composite catalysts

    Science.gov (United States)

    Rajamanickam, D.; Shanthi, M.

    2014-07-01

    The photocatalytic activity and the promoting effect of titania (TiO2) by commercial activated carbon (CAC) for removing the pollutant in wastewater were investigated. The TiO2/CAC composite photocatalysts with various ratios of CAC to TiO2 were prepared by sol-gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area measurement methods. The photocatalytic activity of TiO2/CAC was investigated for the degradation of Sunset Yellow (SY) in aqueous solution using UV-A light. The TiO2/CAC is found to be more efficient than prepared TiO2 and TiO2-P25 at pH 7 for the mineralization of SY. The synergism between TiO2 and CAC may increase the catalytic activity. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The mineralization of SY has been confirmed by COD measurements. The catalyst is found to be reusable.

  4. Synthesis and spectral study of new azo dye and its iron complexes derived from 2-naphthol and 2-amino-3-hydroxypyridine

    Energy Technology Data Exchange (ETDEWEB)

    G, Vidya V., E-mail: sadasivan.v@gmail.com; Sadasivan, V., E-mail: sadasivan.v@gmail.com [University College, M G Road, Palayam, Thiruvananthapuram 695 034, Kerala (India); Meena, S. S., E-mail: ssingh@barc.gov.in; Bhatt, Pramod, E-mail: ssingh@barc.gov.in [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2014-10-15

    An azodye C{sub 5}H{sub 12}N{sub 3}O{sub 2} [LH] is synthesised by coupling diazotised 2-amino-3-hydroxy pyridine with 2-naphthol in ice cold condition. The Fe(II)and Fe(III) complexes were prepared by mixing ethanol solution of metal salt and azodye in 1:2 molar ratio. The dye and metal complexes are structurally characterised by elemental analysis, molar conductance, magnetic susceptibility measurements and spectral techniques like IR, UV-Vis, and Mössbauer analysis. Analytical data suggests the stoichiometry as [FeL{sub 2}Cl(H{sub 2}O)] for Fe(III) complex and [FeL{sub 2}(H{sub 2}O)] for Fe(II) complex. The IR spectral data suggests that [L{sup −}] is acting as a uninegative bidentate ligand. A high spin octahedral geometry is tentatively proposed for both the complexes with respect to the above studies.

  5. Photoinduced phenomena in azo-dyed gelatine films

    International Nuclear Information System (INIS)

    In this work a photoinduced properties of azo-dye doped gelatine films were studied. Gelatine is the oldest polymeric matrix, which is used in holography and photography. Preparation of these films is simple and cheap, but ingredients aren't toxic. Films were synthesized using gelatine and azo-dye -Disperse Red13. Non- aqueous solvents - dimethyl sulfoxide and acetic acid, were used. Films were coated on glass plates using applicator with layer thickness 30, 60, 90 μm and then were heated in vacuum chamber. Azo-dyed gelatine films were illuminated by 532nm laser radiation. Photoinduced birefringence and photoinduced dichroism dependence on films ingredients ratio, laser light intensity and sample treatment temperature were investigated. Holographic recording on these films was performed in dependence on recording beam intensity and polarization. Volume polarization gratings and direct surface relief formation were studied by measuring diffraction efficiency with 660nm diode laser radiation. The obtained surface relief was investigated by AFM.

  6. 超临界水氧化处理偶氮染料废水的实验研究%Experimental study on supercritical water oxidation of azo dye wastewater

    Institute of Scientific and Technical Information of China (English)

    张洁; 王树众; 郭洋; 徐东海; 公彦猛; 唐兴颖; 王玉珍

    2011-01-01

    For exploring the transformation mechanism of azo group during the oxidation reaction, the supercritical water oxidation of the azo dye C. I. Reactive Orange 7 was investigated in a batch reactor. Temperature, oxidant coefficient, initial COD mass concentration, reaction time and solution pH value were selected as process parameters and the total nitrogen removal rate and ammonia-nitrogen mass concentration as the responses. Central Composite Design ( CCD) method was employed for the experimental design, of which an experimental matrix of five-factorial, five-level CCD consisting of 22 experimental runs was obtained. The experimental results were simulated and analyzed by response surface methodology. A quadratic polynomial equation was established for describing the relationship between the total nitrogen removal rate and five process parameters. The analysis of individual and interactive effects of the five variables on responses was conducted in accordance with the simulated equation. The experimental results demonstrate that during the supercritical water oxidation for C. I. Reactive Orange 7, total nitrogen degrades obviously, which can reach 20. 10%~64.16%, but NH3-N mass concentration is rarely produced. Moreover, the five variables all made a positive one-order contribution on total nitrogen removal rate.%在间歇式反应器中进行偶氮染料C.I.活性橙7的超临界水氧化实验,探索染料分子中的偶氮基团在氧化反应中的转化规律.选取反应温度、氧化系数、初始COD质量浓度、反应时间和pH值为过程参数,总氮去除率和氨氮质量浓度为响应量,通过中心组合设计方法进行实验设计,设计了一个五因素、五水平包含22个实验点的实验矩阵.采用响应面分析法对实验结果进行模拟及分析,建立了总氮去除率与5个过程参数关系的二次多项式数学模型,分析了各个参数单独的及相互作用对总氮去除率的影响.实验结果表明:在实验

  7. Relationship of chemical structures of textile dyes on the pre-adaptation medium and the potentialities of their biodegradation by Phanerochaete chrysosporium

    OpenAIRE

    Martins, M. Adosinda M.; Queiroz, Maria João R. P.; Silvestre, Armando J. D.; Lima, Nelson

    2002-01-01

    Azo dye derivatives of azobenzene constitute the largest group of dyes used in the textile industry and possess recalcitrant chemical groups, such as those of azo and sulphonic acid. Some microorganisms are able to degrade these aromatic compounds. In the present work, decolourisation of culture media containing azo dyes by the ligninolytic fungus Phanerochaete chrysosporium was achieved under nitrogenlimited conditions. The dyes used in the study are derivatives of meta- or para-ami...

  8. 气液混合脉冲放电体系中偶氮染料的脱色效果%Decoloration of azo dye in a hybrid gas-liquid pulsed discharge system

    Institute of Scientific and Technical Information of China (English)

    王慧娟; 储金宇; 肖思思; 吴春笃

    2011-01-01

    为了深入探究水包气式气液混合脉冲放电体系中各参数对有机物降解效果的影响,建立了多针一板电极形式的气液混合脉冲放电等离子体体系,以典型的偶氮染料——酸性橙Ⅱ(A07)为目标物,考察该体系中影响染料脱色效果的关键因素。研究结果表明,气液混合脉冲放电体系中与脉冲电源输入功率有关的因素(脉冲电压峰值和脉冲频率)对A07脱色效果影响明显。随着脉冲电压峰值和脉冲频率的增加,A07溶液的脱色效率和相应的准一级降解动力学常数增加。在较高的脉冲电压峰值(30kV)和脉冲频率(75Hz)条件下,10mg/LA07溶液的脱色效率和准一级降解动力学常数分别达到r92.7%和3.50×10~/min。同时,研究证明酸性溶液条件较利于染料脱色。%In order to explore in depth the effects of parameters, such as electric parameters (pulsed voltage, pulse frequency and pulse power) , gas parameters (gas varieties and gas bubbling rate) and solution parameters (initial pH value and conductivity value) etc. , in the hybrid gas-liquid pulsed discharge plasma system on organic compounds degradation, a multi-needle-to-plate hybrid gas-liquid pulsed discharge plasma system was established. In the research, the typical azo dye Acid Orange 7 (AO7) was chosen as the target pollutant and an experimental system was set up to review the key factors for AO7 decoloration in the hybrid gas-liquid pulsed discharge plasma system. The obtained results reveal that the factors concerned with the input power of the pulsed power supply, such as pulse voltage peak value and pulse frequency, have distinct effect on the decol- oration of AOT. With the increase of the pulse voltage peak value and the pulse frequency, the decoloration rate of AO7 and the pseudo-first-order kinetic constant of AO7 oxidation increased. Under the condition of 30 kV pulse voltage peak value, 50 Hz

  9. Fullerene-catalyzed reduction of azo derivatives in water under UV irradiation

    KAUST Repository

    Guo, Yong

    2012-09-27

    Metal-free fullerene (C60) was found to be an effective catalyst for the reduction of azo groups in basic aqueous solution under UV irradiation in the presence of NaBH4. Use of NaBH4 by itself is not sufficient to reduce the azo dyes without the assistance of a metal catalyst such as Pd and Ag. Experimental and theoretical results suggest that C 60 catalyzes this reaction by using its vacant orbital to accept the electron in the bonding orbital of azo dyes, which leads to the activation of the N=N bond. UV irradiation increases the ability of C60 to interact with electron-donor moieties in azo dyes. Filling a vacancy: Experimental and theoretical methods have been combined to show that C60-catalyzed reductions of azo compounds form aromatic amines under UV irradiation (see scheme). The obtained results show that C60 acts as an electron acceptor to catalyze the reduction of azo compounds, and the role of UV irradiation is to increase the ability of C60 to interact with electron-donor moieties in azo compounds. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. The Hydractinia echinata Test-System. III: Structure-Toxicity Relationship Study of Some Azo-, Azo-Anilide, and Diazonium Salt Derivatives

    Directory of Open Access Journals (Sweden)

    Sergiu Adrian Chicu

    2014-07-01

    Full Text Available Structure-toxicity relationships for a series of 75 azo and azo-anilide dyes and five diazonium salts were developed using Hydractinia echinata (H. echinata as model species. In addition, based on these relationships, predictions for 58 other azo-dyes were made. The experimental results showed that the measured effectiveness Mlog(1/MRC50 does not depend on the number of azo groups or the ones corresponding to metobolites, but it is influenced by the number of anilide groups, as well as by the substituents’ positions within molecules. The conformational analysis pointed out the intramolecular hydrogen bonds, especially the simple tautomerization of quinoidic (STOH or aminoidic (STNH2 type. The effectiveness is strongly influenced by the “push-pull” electronic effect, specific to two hydroxy or amino groups separated by an azo moiety (double alternate tautomery, (DAT, to the –COOH or –SO3H groups which are located in ortho or para position with respect to the azo group. The levels of the lipophylic/hydrophilic, electronic and steric equilibriums, pointed out by the Mlog(1/MRC50 values, enabled the calculation of their average values Clog(1/MRC50 (“Köln model”, characteristic to one derivative class (class isotoxicity. The azo group reduction and the hydrolysis of the amido/peptidic group are two concurrent enzymatic reactions, which occur with different reaction rates and mechanisms. The products of the partial biodegradation are aromatic amines. No additive or synergic effects are noticed among them.

  11. Disperse Dyes Based on Thiazole, Their Dyeing Application on Polyester Fiber and Their Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    S. K. Zadafiya

    2013-01-01

    Full Text Available Various diazotized aryl amines were coupled with N-(4-nitrophenyl-2-[(4-phenyl-1,3-thiazol-2-ylamino]acetamide to give the corresponding various azo disperse dyes (D1-D13. These dyes were applied to polyester fiber by HTHP method and their fastness properties were evaluated. Dyes were characterized by IR, elemental analysis, and NMR spectral studies. These dyes showed very good antibacterial and antifungal activities.

  12. Disperse Dyes Based on Thiazole, Their Dyeing Application on Polyester Fiber and Their Antimicrobial Activity

    OpenAIRE

    Zadafiya, S. K.; J. H. Tailor; Malik, G. M.

    2013-01-01

    Various diazotized aryl amines were coupled with N-(4-nitrophenyl)-2-[(4-phenyl-1,3-thiazol-2-yl)amino]acetamide to give the corresponding various azo disperse dyes (D1-D13). These dyes were applied to polyester fiber by HTHP method and their fastness properties were evaluated. Dyes were characterized by IR, elemental analysis, and NMR spectral studies. These dyes showed very good antibacterial and antifungal activities.

  13. Synthesis of Some Monoazo Disperse Dyes Derived from Aminothienochromene

    Directory of Open Access Journals (Sweden)

    Morsy Ahmed El-Apasery

    2013-07-01

    Full Text Available A series of azo disperse dyes based on aminothienochromene were synthesized. The fastness properties of the dyed samples were measured. Most of the dyed fabrics tested displayed excellent washing and perspiration fastness and moderate light fastness.

  14. Utilization of white rot fungi for textile dye decolourisation under alkaline condition and high salt concentration in solid medium

    OpenAIRE

    Ottoni, C. A.; Santos, Cledir; Lima, Nelson

    2010-01-01

    A large amount of azo dyes are used for dyeing textiles. However, the dyes contaminate wastewaters and need to be treated. This is important because of the aesthetic, toxic and carcinogenic effects of the affected waters. Recently there has been an increase in interest in using white rot fungi (wrf) which degrade xenobiotic compounds including azo dyes. Wrf degrade lignin and others recalcitrant molecules using nonspecific extracellular enzymes. Four white rot fungi...

  15. DECOLOURIZATION OF SELECTED PROCION DYE USING FUNGI, ACREMONIUM CHRYSOGENUM A COMPARISON WITH PHYSICAL ADSORBENTS

    Directory of Open Access Journals (Sweden)

    M.Prasad Naidu

    2015-12-01

    Full Text Available Azo dyes, based on aromatic amines, may contain these amines as impurities introduced during the manufacturing process. Aromatic amines may also be present as a result of thermal or photochemical degradation of azo dyes. The more stable derivatives contain two aryl groups. As a consequence of ?-delocalization, aryl azo compounds have vivid colors, especially reds, oranges, and yellows. Therefore, they are used as dyes, and are commonly known as azo dyes, an example of which is Disperse Orange. Some azo compounds, eg. methyl orange, are used as acid-base indicators due to the different colors of their acid and salt forms. The development of azo dyes was an important step in the development of the chemi azo colorants range in shade from greenish yellow to orange, red, violet and brown. The colours depend largely on the chemical constitution, whereas different shades rather depend on the physical properties. However, the important disadvantage limiting their commercial application is that most of them are red and none are green. The inoculum was prepared by adding 10ml of saline to the culture tube, which contain the Acremoniumchrysogenum. The present study designed to study the degradation of common laboratory dyes using fungi, acremonium chrysogenum. The dye selected was procion red. The selected dye procion red can be toxic in its secondary reactive form so there is a great need of them to be removed from the environment.

  16. Fungal mechanisms of textile dyes biodegradation

    OpenAIRE

    Lima, Nelson; Ottoni, C. A.; Lima, Luís; Santos, C.

    2010-01-01

    Reactive dyes are widely used in the textile industry. Coloured effluents from dyestuff and textile industries. the major producers and users of azo dyes. not only produce visual pollution but con also be detrimental to life. as they ore usually resistant to biological treatment. Additionally. fungi, mainly white rot fungi. have shown the ability to degrade numerous aromatic organopollutants. including textile dyes. via oxidative mechanisms till their complete mineralisation. ...

  17. Decolorization of acid and basic dyes: understanding the metabolic degradation and cell-induced adsorption/precipitation by Escherichia coli.

    Science.gov (United States)

    Cerboneschi, Matteo; Corsi, Massimo; Bianchini, Roberto; Bonanni, Marco; Tegli, Stefania

    2015-10-01

    Escherichia coli strain DH5α was successfully employed in the decolorization of commercial anthraquinone and azo dyes, belonging to the general classes of acid or basic dyes. The bacteria showed an aptitude to survive at different pH values on any dye solution tested, and a rapid decolorization was obtained under aerobic conditions for the whole collection of dyes. A deep investigation about the mode of action of E. coli was carried out to demonstrate that dye decolorization mainly occurred via three different pathways, specifically bacterial induced precipitation, cell wall adsorption, and metabolism, whose weight was correlated with the chemical nature of the dye. In the case of basic azo dyes, an unexpected fast decolorization was observed after just 2-h postinoculation under aerobic conditions, suggesting that metabolism was the main mechanism involved in basic azo dye degradation, as unequivocally demonstrated by mass spectrometric analysis. The reductive cleavage of the azo group by E. coli on basic azo dyes was also further demonstrated by the inhibition of decolorization occurring when glucose was added to the dye solution. Moreover, no residual toxicity was found in the E. coli-treated basic azo dye solutions by performing Daphnia magna acute toxicity assays. The results of the present study demonstrated that E. coli can be simply exploited for its natural metabolic pathways, without applying any recombinant technology. The high versatility and adaptability of this bacterium could encourage its involvement in industrial bioremediation of textile and leather dyeing wastewaters. PMID:26062529

  18. Degradation of dyes with microorganisms : studies with ascomycete yeasts

    OpenAIRE

    Ramalho, Patrícia A.

    2005-01-01

    Tese de doutoramento em Ciências. The capabilities of several yeasts were explored for the degradation of textile azo dyes. Through the initial work with Candida zeylanoides it has been possible to improve the composition of the culture medium to achieve the decolourisation of several model azo dyes. Total decolourisation times observed in culture media supplemented with 0.2mM dye ranged from 40 to 60 h. The initial decolourisation rates were 14–52µmol.(g dry cell)-¹.h-¹, depending on dye ...

  19. Isolation and identification of halophilic bacteria strain Halomonas elogata and its application on degradation of an azo dye Reactive Blue BRF%极端嗜盐菌Halomonas elogata的分离鉴定及其降解偶氮染料活性兰BRF的条件优化研究

    Institute of Scientific and Technical Information of China (English)

    韦娜; 张前前; 杜宗军; 张栋梅

    2012-01-01

    An extremely halophilic bacterial strain was acclimated,isolated and purified from the saline-alkali soil obtained from the Xinjiang Uygur Autonomous Region.It was identified as Halomonas elogata based on its morphology,physiological-biochemical characteristics and 16S rDNA sequence analysis.Subsequently,the influencing factors on the azo dye degradation were explored.Degradation effects in a series of salt concentrations were compared.In single factor experiments,the influencing factors of inoculation volume,initial azo dye concentration and pH were tested respectively under inoculation conditions of 30℃ and 5% salinity.The orthogonal experiments L9(33) were designed to obtain the optimal experiment conditions.Finally,the degradation products were estimated by the UV-vis spectra.The results indicated that the strain Halomonas elogata was tolerant to a wide salinity ranging from 0 to 32%,while the optimal salinity for its cell growth was from 5% to 20%.Among salinity range of 3% to 25%,the degradation rate increased initially and then decreased with the salinity increasing,and the best degradation effect happened when the salinity was 5%.At 30℃ and salinity of 5%,the optimal conditions for degradation of azo dye Reactive Blue BRF were found as follows:initial concentration of 100 mg · L-1 for azo dye,pH 7 and initial inoculation volume of 5% for the strain.Under these conditions,an 88.62% degradation of azo dye was achieved over a time period of 72 hours.The UV-vis spectra revealed that the degradation products were quite different from Reactive Blue BRF.There was no peak in visible region and its n-hexane extraction,while its dichloromethane extracts exhibited two UV absorption peaks implying that degradation products might be polar aromatic amines and heterocyclic compounds.Mass spectrometry results revealed that the degradation products included polar compounds such as benzyl diamine and 2,6-diamino-phenol.%从新疆地区土壤中经驯化、分离

  20. Isolation and Screening of Water Microbes for Decolourisation of Textile Dye Waste

    OpenAIRE

    J. K. Singh,; Ranjan, R.; Pranay P. Pankaj*

    2016-01-01

    Azo dyes are widely used in textile industry. Unused dyes, consisting mainly non biodegradable released along with waste water streams without any proper pre-treatment which cause nuisance for environment and accumulate in flora as well as fauna. These also exhibit allergic, carcinogenic and mutagenic properties for human beings. Isolation and screening of azo dye degrading bacteria are economic in biodegradation and detoxification. In the present study, 200 waste water samples were collected...

  1. 40 CFR 721.9538 - Lithium salt of sulfophenyl azo phenyl azo disulfostilbene (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Lithium salt of sulfophenyl azo phenyl... Significant New Uses for Specific Chemical Substances § 721.9538 Lithium salt of sulfophenyl azo phenyl azo... substance identified generically as lithium salt of sulfophenyl azo phenyl azo disulfostilbene (PMN...

  2. Adsorption of acid dyes on Natural wool yarns

    International Nuclear Information System (INIS)

    The adsorption isotherms have been developed for two acid dyes (red and yellow azo dyes) individually on natural wool yarns. The study revealed strong interactions between the effects of solution ph, temperature and initial dye concentration. Equilibrium uptake data were fitted to the Redlich- Peterson isotherm model. The adsorption behaviour approaches Langmuir model at favourable conditions of higher temperature and lower ph for yellow dye. (authors). 9 refs., 5 tabs., 8 figs

  3. Solubilidade de corantes azo

    OpenAIRE

    Leal, Cláudia Sofia Mendes

    2011-01-01

    Os corantes são substâncias, de origem natural ou sintética, que conferem cor aos materiais. A quantidade de corantes proveniente dos processos de tingimento que é lançada no ambiente ainda é muito grande, nomeadamente de corantes azo. São poucos os valores de solubilidade publicados, destes corantes, apesar de a solubilidade ser um parâmetro físico-químico importante, quer nos processos de tingimento quer na disponibilidade do corante no meio ambiente. Neste trabalho é efectuada uma revisão ...

  4. Reactividad Química de los Azo Colorantes Amarillo Anaranjado y Rojo Allura mediante Descriptores Globales y la Función de Fukui Chemical Reactivity of the Azo dyes Sunset Yellow and Allura Red by Global Descriptors and the Fukui Function

    Directory of Open Access Journals (Sweden)

    Adolfo E Ensuncho

    2012-01-01

    Full Text Available Se calcularon descriptores globales y locales de la reactividad para los colorantes amarillo anaranjado y rojo allura con el fin de analizar su reactividad química intrínseca. Los cálculos computacionales se llevaron a cabo tanto en vacio como en la fase acuosa, la cual se representó por medio de una constante dieléctrica de 78.5 e introducida por el modelo de solvente del continuo polarizado. Los resultados mostraron que el colorante rojo allura es menos susceptible a la adición nucleofílica que el amarillo anaranjado, ya que los sustituyentes electrodonadores metilo y metoxilo disminuyen la capacidad del grupo azo para aceptar electrones. El análisis de la función condensada de Fukui para el ataque nucleofílico e índice de electrofilicidad local, mostraron que el sitio preferido de ataque del agente reductor (ión bisulfito fue C4, lo cual estuvo en concordancia con los reportes experimentales.In the present work local and global descriptors of the reactivity were calculated for sunset yellow and allura red to analyze its intrinsic reactivity. The computational calculations were carried out in vacuum and aqueous phase. The aqueous phase is represented by a dielectric constant of 78.5, introduced by polarizable continuum model. The results show that allura red is less susceptible to nucleophilic addition than sunset yellow, because the electrodonor substituents methyl and methoxy decrease the capability of the azo group to accept electrons. The analysis of condensed Fukui function for a nucleophilic attack and local electrophilicity index showed that the preferred direction of attack the reducing agent (bisulfite ion occurs on C4, which was in good agreement with experimental reports.

  5. Investigation of Iron Powder, Hydrogen Peroxide and Iron Hydrogen Peroxide for Removal of Acid Yellow Powder 36 Dye from Aqueous Solutions

    OpenAIRE

    Sardar, M.; A Sheikh Mohammadi; A.R Yazdanbakhsh; H Mohammad; M Zarabi

    2010-01-01

    "n "nBackgrounds and Objectives: A great part of organic compounds cause more pollution in natural  waters meet, are chemical dye material. Azo dyes have more usage in different industries. Azo dyes not only give undesirable dye to the water but also have mutation potential and carcinogenesis effects in human and cause the production of toxic substances in water environments.The purpose of this study is investigation of iron powder, hydrogen peroxide and iron powder-hydrogen peroxide pro...

  6. Method for the Determination of Sudan Dyes in Foods-High Performance Liquid Chromatography Jointly Issued by AQSIQ and SAC

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Sudan Red are the chemosynthesis dyes of series of azo, which are mainly used as coloring additives in manufacturing of some products, such as the wax, the oil-dyes, the petrol, and etc. In the process of food production, Sudan Dyes are banned to be used as food dyes in our country.

  7. Degradation products of the artificial azo dye, Allura red, inhibit esterase activity of carbonic anhydrase II: A basic in vitro study on the food safety of the colorant in terms of enzyme inhibition.

    Science.gov (United States)

    Esmaeili, Sajjad; Ashrafi-Kooshk, Mohammad Reza; Khaledian, Koestan; Adibi, Hadi; Rouhani, Shohre; Khodarahmi, Reza

    2016-12-15

    Allura red is a widely used food colorant, but there is debate on its potential security risk. In the present study, we found that degradation products of the dye were more potent agents with higher carbonic anhydrase inhibitory action than the parent dye. The mechanism by which the compounds inhibit the enzyme activity has been determined as competitive mode. In addition, the enzyme binding properties of the compounds were investigated employing different spectroscopic techniques and molecular docking. The analyses of fluorescence quenching data revealed the existence of the same binding site for the compounds on the enzyme molecule. The thermodynamic parameters of ligand binding were not similar, which indicates that different interactions are responsible in binding of the parent dye and degradation products to the enzyme. It appears that enzyme inhibition should be considered, more seriously, as a new opened dimension in food safety. PMID:27451209

  8. Enhanced photocatalytic activity of silver metallized TiO2 particles in the degradation of an azo dye methyl orange: Characterization and activity at different pH values

    International Nuclear Information System (INIS)

    The photocatalytic activity of silver deposited Degussa P25 titanium dioxide (Ag-DP25) in the photodegradation of methyl orange (MO) was investigated. The photocatalysts were characterized using PXRD, SEM, EDX, FTIR and UV-vis spectrophotometer. The obtained results show that the silver (Ag0) deposited TiO2 exhibited visible light plasmon absorption band. The degradation experiment reveals that the catalytic property of Ag-DP25 in the degradation of MO is more efficient than that of commercially available Degussa P25 TiO2 (DP25) samples. The improvement of Ag-DP25 catalyst efficiency strongly depends on the content of silver (Ag) deposits. The present study shows that the degradation process is dominated by Ag-TiO2 photocatalytic system, complying with pseudo-first order rate law. The higher rate of photodegradation observed on Ag-DP25 at pH 6.6 can be correlated to the ratios of the concentrations of the ionized to the neutral dye molecules and also to the higher concentration of hydroxylated surface, which are able to effectively scavenge photogenerated valence band holes. Accumulation of the holes in the semiconductor particles increases the probability of formation of excited oxygen atom which is a reactive species readily oxidizing the organic dye molecule. The reduction of pH during the course of the reaction is attributed to the complete mineralization of the dye.

  9. Determinação de corantes marcadores do tipo azo e antraquinona em combustíveis por cromatografia líquida com detecção eletroquímica Determination of azo and anthraquinone dyes in fuels sample using hplc with electrochemical detection

    OpenAIRE

    Magno Aparecido Gonçalves Trindade; Daniel Rinaldo; Wagner Vilegas; Maria Valnice Boldrin Zanoni

    2010-01-01

    An analytical method based on high-performance liquid chromatography with electrochemical detection has been developed and applied to the determination of Solvent blue 14 (SA-14) and Solvent red 24 (SV-24) in fuel samples. The dyes were better separated on C18 column, using a mobile phase composed of acetonitrile and ammonium acetate (90:10, v/v). Detection was carried out at an oxidation potential of +0.85V. The detector response was linear at concentration range of 7.50×10-8 - 1.50×10-6 mol...

  10. Anaerobic/aerobic degradation of a textile dye wastewater

    OpenAIRE

    Loyd, Chapman Kemper

    1992-01-01

    Consumer demands have led to the development of new, more stable textile dyes. These dyes, many of the azo type, are often incompletely degraded/removed in wastewater treatment plants, leading to the discharge of highlycolored effluents to rivers and streams. Concerns by downstream users of that water have led to enactment of effluent color and toxicity standards for plants that treat textile dye wastewater. Both anaerobic and aerobic biological degradation of a...

  11. Dyeing of UV irradiated cotton and polyester fabrics with multifunctional reactive and disperse dyes

    Directory of Open Access Journals (Sweden)

    Ijaz Ahmad Bhatti

    2016-03-01

    Full Text Available The dyeing behaviour of UV irradiated cotton and polyester fabrics using multifunctional reactive and disperse dyes has been investigated. The plain, woven, mercerized, bleached, cotton and polyester fabrics were exposed to UV radiation (180 w, 254 nm for 30, 60, 90 and 120 min. Dyeing was performed using irradiated fabric with a dye solution of un-irradiated reactive and disperse/azo dyes. The dyeing parameters such as, temperature, time, pH and salt concentration have been optimized. The colour strength values of dyed fabrics were evaluated by comparing irradiated and un-irradiated cotton and polyester fabrics in CIE Lab systems using spectra flash SF600. Finally ISO standard methods were employed to observe the effect of UV radiation on fastness properties. It was found that UV radiation has a potential to improve the colour strength values of cotton and polyester fabrics by using reactive and disperse dyes.

  12. 40 CFR 721.5930 - Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium...

    Science.gov (United States)

    2010-07-01

    ...)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic name). 721.5930 Section 721... Phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo(substituted phenyl)azo, sodium salt (generic... identified generically as phenylenebis[imino (chlorotriazinyl)imino(substituted naphthyl)azo...

  13. Preparation and characterization of grafted polyethylene based azo-polymer films

    International Nuclear Information System (INIS)

    A series of grafted azo-polymers was prepared from commercial low density polyethylene thin plates (PE). Polyethylene was reacted in the presence of acryloyl chloride using gamma irradiation to give precursor grafted polymers. These materials were esterified in the presence of six different commercial azo-dyes: (E)-2-(ethyl(4-((4-nitrophenyl)diazenyl)phenyl)amino)ethanol (Disperse Red-1, DR-1), (E)-2-((4-((2-chloro-4-nitrophenyl)diazenyl)phenyl)(ethyl)amino)ethanol (Disperse Red-13, DR-13), (E)-2,2'-(4-((4-nitrophenyl)diazenyl)phenylazanediyl)diethanol (Disperse Red-19, DR-19), (E)-4-((4-nitrophenyl)diazenyl)aniline (Disperse Orange-3, DO-3), 4-((E)-(4-((E)-phenyldiazenyl)naphthalen-1-yl)diazenyl)phenol (Disperse Orange-13, DO-13) and 2-methyl-4-((E)-(4-((E)-phenyldiazenyl)phenyl)diazenyl)phenol (Disperse Yellow-7, DY-7) to give the expected grafted azo-polymer films. The obtained polymers were fully characterized; their thermal, optical properties and morphology were studied. In particular, the influence of the irradiation conditions and the incorporated azo-dye on the polymer properties is discussed.

  14. Preparation and characterization of grafted polyethylene based azo-polymer films

    Energy Technology Data Exchange (ETDEWEB)

    Pilar Carreon-Castro, Maria del, E-mail: pilar@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Rivera, Ernesto [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Jesus Cruz, Jose de; Zavaleta, Gerardo [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico); Gutierrez-Nava, Manuel [Instituto de Investigaciones en Materiales, Universidad Nacional Autonoma de Mexico, Circuito Exterior Ciudad Universitaria C.P. 04510, Mexico D.F. (Mexico)

    2010-05-31

    A series of grafted azo-polymers was prepared from commercial low density polyethylene thin plates (PE). Polyethylene was reacted in the presence of acryloyl chloride using gamma irradiation to give precursor grafted polymers. These materials were esterified in the presence of six different commercial azo-dyes: (E)-2-(ethyl(4-((4-nitrophenyl)diazenyl)phenyl)amino)ethanol (Disperse Red-1, DR-1), (E)-2-((4-((2-chloro-4-nitrophenyl)diazenyl)phenyl)(ethyl)amino)ethanol (Disperse Red-13, DR-13), (E)-2,2'-(4-((4-nitrophenyl)diazenyl)phenylazanediyl)diethanol (Disperse Red-19, DR-19), (E)-4-((4-nitrophenyl)diazenyl)aniline (Disperse Orange-3, DO-3), 4-((E)-(4-((E)-phenyldiazenyl)naphthalen-1-yl)diazenyl)phenol (Disperse Orange-13, DO-13) and 2-methyl-4-((E)-(4-((E)-phenyldiazenyl)phenyl)diazenyl)phenol (Disperse Yellow-7, DY-7) to give the expected grafted azo-polymer films. The obtained polymers were fully characterized; their thermal, optical properties and morphology were studied. In particular, the influence of the irradiation conditions and the incorporated azo-dye on the polymer properties is discussed.

  15. 40 CFR 721.10107 - Naphthalenedisulfonic acid, [amino-hydroxy-[(substituted)azo-sulfo-naphthaleneyl]azo]-hydroxy...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Naphthalenedisulfonic acid, azo... Significant New Uses for Specific Chemical Substances § 721.10107 Naphthalenedisulfonic acid, azo]-hydroxy... chemical substance identified generically as naphthalenedisulfonic acid, azo]-hydroxy- , metal salt (PMN...

  16. Synthesis and Characterization of Photoresponsive Azo Polyelectrolytes

    Institute of Scientific and Technical Information of China (English)

    WU Lifeng; PENG Huagen; WANG Xiaogong; LIU Deshan; ZHOU Qixiang

    2001-01-01

    Optical active azo polymers are very important functional materials because of their photoresponsive properties.This paper investigates three kinds of aromatic azo polyelectrolytes synthesized by chemical modification of poly(acryloyl chloride)which was prepared by free radical polymerization.Poly was esterified with three different kinds of aromatic azo compounds containing hydroxyl groups to give polymeric intermediates,which were used to prepare the azo polyelectrolytes by hydrolysis.The products were characterized by elementary analysis,IR,1H-NMR,and UV-Vis spectrography.

  17. Nanometer-thick amorphous-SnO2 layer as an oxygen barrier coated on a transparent AZO electrode

    Science.gov (United States)

    Lee, Hee Sang; Woo, Seong Ihl

    2016-07-01

    It is necessary for transparent conducting electrodes used in dye-sensitized or perovskite solar cells to have high thermal stability which is required when TiO2 is coated on the electrode. AZO films with their low-cost and good TCO properties are unfortunately unstable above 300 °C in air because of adsorbed oxygen. In this paper, the thermal stability of AZO films is enhanced by depositing an oxygen barrier on AZO films to block the oxygen. As the barrier material, SnO2 is used due to its high heat stability, electrical conductivity, and transmittance. Moreover, when the SnO2 is grown as amorphous phase, the protective effect become greater than the crystalline phase. The thermal stability of the amorphous-SnO2/AZO films varies depending on the thickness of the amorphous SnO2 layer. Because of the outstanding oxygen blocking properties of amorphous SnO2, its optimal thickness is very thin and it results in only a slight decrease in transmittance. The sheet resistance of the amorphous-SnO2/AZO film is 5.4 Ω sq-1 after heat treatment at 500 °C for 30 min in air and the average transmittance in the visible region is 83.4%. The results show that the amorphous-SnO2/AZO films have thermal stability with excellent electrical and optical properties. [Figure not available: see fulltext.

  18. Study of Modern Nano Enhanced Techniques for Removal of Dyes and Metals

    Directory of Open Access Journals (Sweden)

    Samavia Batool

    2014-01-01

    Full Text Available Industrial effluent often contains the significant amount of hexavalent chromium and synthetic dyes. The discharge of wastewater without proper treatment into water streams consequently enters the soil and disturbs the aquatic and terrestrial life. A range of wastewater treatment technologies have been proposed which can efficiently reduce both Cr(VI and azo dyes simultaneously to less toxic form such as biodegradation, biosorption, adsorption, bioaccumulation, and nanotechnology. Rate of simultaneous reduction of Cr(VI and azo dyes can be enhanced by combining different treatment techniques. Utilization of synergistic treatment is receiving much attention due to its enhanced efficiency to remove Cr(VI and azo dye simultaneously. This review evaluates the removal methods for simultaneous removal of Cr(VI and azo dyes by nanomicrobiology, surface engineered nanoparticles, and nanophotocatalyst. Sorption mechanism of biochar for heavy metals and organic contaminants is also discussed. Potential microbial strains capable of simultaneous removal of Cr(VI and azo dyes have been summarized in some details as well.

  19. Decolourization potential of white-rot fungus Phanerochaete chrysosporium on synthetic dye bath effluent containing Amido black 10B

    OpenAIRE

    Senthilkumar, S.; M. Perumalsamy; H. Janardhana Prabhu

    2014-01-01

    Synthetic azo dyes are extensively used in textile industry and are not easily degraded into the environment due to their complex structure. Due to the low degree of fixation of these dyes to fabrics, more than 10–15% of the dye does not bind to fabrics during colour processing and release into water bodies as effluent cause serious environmental pollution. White-rot fungus is found to be capable of degrading lignin which has a complex structure similar to azo dyes. In this study, the decolou...

  20. Synthesis of a New Optoelectronic Material Based on Oriented Adsorption of Dyes to Nanoparticles Surface

    Institute of Scientific and Technical Information of China (English)

    LI Gui-an; SONG Jian-ping; LI Xiu

    2005-01-01

    Synthesis of the optoelectronic storage material with structure for coating by nanosized metal and azo-dye was reported. The characterization of composites was made by using transmission electron microscope (TEM), ultraviolet-visible spectrometer (UV-Vis) and thermogravity analyzer (TGA). It is found that, due to the specific structure, in which azo-dye molecules are oriented and adsorbed on the spherical surface of nanosized metal, the absorption maximum of azo-dye methyl orange shift towards shorter wavelength band. The experimental results show that the proposed technique here would offer a promising way to synthesize short wavelength optoelectronic storage material by doping of metal nanoparticles coated with dyes in polymer. Furthermore, the composites based on the structure can present excellent thermal properties suitable for the requirements of optical storage. This new type of material is capable of matching semiconductor laser (GaN) in optoelectronic storage technology.

  1. STUDY ON PHOTODYNAMIC AND PHOTORESPONSIVE AZO POLYELECTROLYTES

    Institute of Scientific and Technical Information of China (English)

    Xiao-gong Wang; Li-feng Wu; Qi-xiang Zhou; Lian Li; Srinivasan Balasubraminian; Jayant Kumar; Sukant K. Tripathy

    2000-01-01

    Several kinds of novel azobenzene-containing polyelectrolytes with special molecular design have been developed from acryloyl chloride or epoxy based precursor polymers. The acryloyl chloride based precursor polymer, poly(acryloyl chloride), was prepared by free radical polymerization of acryloyl chloride. The azo polyelectrolytes were prepared by an esterification reaction between the precursor polymer and corresponding azo chromophores containing a reactive hydroxyl group, followed by hydrolysis of the unreacted acyl chloride groups. The epoxy based precursor polymer was prepared by the reaction between 1,4-cyclohexanedimethanol diglycidyl ether and aniline, and postfunctionalized by azo coupling reaction to form azo polymers containing chromophores with ionizable groups. The polyelectrolytes were characterized by elemental analysis, 1H-NMR, IR and UV-Vis spectroscopy. The photodynamic and photoresponsive properties, as well as self-assembly ofthese azo polyelectrolytes are reported in this paper[1].

  2. Treatment of Dye Effluent by Electrochemical and Biological Processes

    OpenAIRE

    Sirasanaganbla Udya Bhanu; Saravanan Arun Kumar; Anand Kuber Parande; Balakrishnan Ramesh Babu

    2011-01-01

    Textile dye wastewater is well known to contain strong colour, high pH, temperature, Chemical Oxygen Demand (COD) and biodegradable materials. The electrochemical treatment of wastewater is considered as one of the advanced oxidation processes, potentially a powerful method of pollution control, offering high removal efficiencies the removal of colour of methyl red azo dye is a challenge in textile industry. The following methods have been adopted for the treatment of real textile wastewater:...

  3. Photo-induced reorientation of molecules in dye micro crystals

    Institute of Scientific and Technical Information of China (English)

    Tariel D. Ebralidze; Nadia A. Ebralidze

    2006-01-01

    Upon massive generation of anisotropic grains of azo dye methyl orange in a gelatin film exposed to active polarized light, a cluster of micro crystals with optical axes of similar orientations has been produced. The anisotropy observed has been found to disappear under exposure to active natural light.

  4. 40 CFR 721.9577 - Chromate(3-), bis[7-[(aminohydroxyphenyl)azo]-3-[[5-(aminosulfonyl)-2-hydroxyphenyl] azo]-4...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Chromate(3-), bis -3- azo]-4-hydroxy-2-naphthalene sulfonato (3-)]-,- azo]-4-hydroxy-7- -1-propenyl]azo]-2-naphthalenesulfonato(3-)]-, trisodium (9CI... Substances § 721.9577 Chromate(3-), bis -3- azo]-4-hydroxy-2-naphthalene sulfonato (3-)]-,-...

  5. Surface relief grating recording in azo polymer films

    International Nuclear Information System (INIS)

    In this work holographic recording of surface relief grating in organic Poly(Disperse Red 1 – methacrylate) thin films was studied. In this compound azo dye is chemically bonded to monomers making mass transport very efficient in the presence of optical field gradient. Sample preparation was performed using different solvents and coating methods. In the obtained samples holographic recording was performed by solid-state diode pump laser with 532 nm wavelength. Polarization grating and surface relief grating formation was studied by diode laser with 660 nm wavelength. Diffraction efficiency's dependence on read-out laser beam polarization state was investigated. The depth of surface relief grating was measured by AFM and studied in dependence on recording beam intensity, exposure and thickness of the sample

  6. Improving temperature-stable AZO-Ag-AZO multilayer transparent electrodes using thin Al layer modification

    International Nuclear Information System (INIS)

    The thermal stability of AZO/Al/Ag/Al/AZO (5A) compared with AZO/Ag/AZO (3A) electrodes was significantly improved by introducing a thin Al layer at the interface between Ag and AZO layers. The rapidly deteriorated sheet resistance of 3A compared with 5A electrodes is roughly consistent with the XRD results of weaker intensity of the (111) Ag peak of 3A after annealing for 20 h at 300 or 500 °C for 10 min. The improved thermal stability of the 5A electrode is ascribed to the limitation function of Al atoms on Ag diffusion into the AZO layer. The polymer solar cells based on 5A compared with ITO electrodes showed a similar efficiency.

  7. Enhanced photoinduced birefringence in polymer-dye complexes: Hydrogen bonding makes a difference

    OpenAIRE

    Priimagi, Arri; Kaivola, Matti; Rodriguez, Francisco J.; Kauranen, Martti

    2007-01-01

    The authors demonstrate that photoinduced birefringence in azo-dye-doped polymers is strongly enhanced by hydrogen bonding between the guest molecules and the polymer host. The primary mechanism behind the enhancement is the possibility to use high dye doping levels compared to conventional guest-host systems because dye aggregation is restrained by hydrogen bonding. Moreover, hydrogen bonding reduces the mobility of the guest molecules in the polymer host leading to a larger fraction of the ...

  8. Treatment of a Textile Effluent from Dyeing with Cochineal Extracts Using Trametes versicolor Fungus

    OpenAIRE

    Gabriela Arroyo-Figueroa; Graciela M. L. Ruiz-Aguilar; Leticia López-Martínez; Guillermo González-Sánchez; Germán Cuevas-Rodríguez; Refugio Rodríguez-Vázquez

    2011-01-01

    Trametes versicolor (Tv) fungus can degrade synthetic dyes that contain azo groups, anthraquinone, triphenylmethane polymers, and heterocyclic groups. However, no references have been found related to the degradation of natural dyes, such as the carminic acid that is contained in the cochineal extract. Experiments to determine the decolorization of the effluent used in the cotton dyeing process with cochineal extract by means of Tv fungus were done. Treatments to determine decolorization in t...

  9. Bioreactor for the decolourisation of textile dye using ligninolytic fungi under high alkaline and salt conditions

    OpenAIRE

    Ottoni, C. A.; Lima, Luís; Santos, C.; Lima, Nelson

    2011-01-01

    The wastewater of textile industry contains not only dyes but also salts, surfactants and others substances and as extreme pH values. Among all dyes and pigments azo dyes are claimed to be between 60 to 70% of the environmental pollutants. Nowadays, environmental regulations in most countries require textile effluents to be decolourised before discharging. This led to the study of innovative and environmental friendly technologies. The extracellular ligninolytic enzyme system o...

  10. Empirical models for the decoloration of dyes in an electrochemical batch cell

    OpenAIRE

    Pepió Viñals, Montserrat; Gutiérrez Bouzán, María Carmen

    2011-01-01

    Among several types of textiles colorants, reactive dyes represent about 30 50% of the total market share, and the most common group used as chromophore is the azo group (70%), followed by anthraquinone. The removal of such dyes from wastewater is a problem in textile mills. Electrochemical treatment has proven to be an interesting technique for removing dyes from wastewater, as it does not require any added chemical reagents. Generally, this technique is applied to obtain partial dy...

  11. AZO-Ag-AZO transparent electrode for amorphous silicon solar cells

    International Nuclear Information System (INIS)

    Metal-based transparent electrodes can be fabricated at low temperatures, which is crucial for various substrate materials and solar cells. In this work, an oxide-metal-oxide (OMO) transparent electrode based on aluminum zinc oxide (AZO) and silver is compared to AZO layers, fabricated at different temperatures and indium tin oxides. With the OMO structure, a sheet resistance of 7.1/square and a transparency above 80% for almost the entire visible spectrum were achieved. The possible application of such electrodes on a textured solar cell was demonstrated on the example of a rough ZnO substrate. An OMO structure is benchmarked in a n-i-p amorphous silicon solar cell against an AZO front contact fabricated at 200 °C. In the experiment, the OMO electrode shows a superior performance with an efficiency gain of 30%. - Highlights: • Multilayer transparent electrode based on aluminum zinc oxide (AZO) and Ag • Comparison of AZO-Ag-AZO transparent electrode to AZO and indium tin oxide • Performance of AZO-Ag-AZO transparent electrodes on textured surfaces • Comparison of amorphous silicon solar cells with different transparent electrodes

  12. A Study on 4,4′-Diaminobenzene Sulfonanilide(DABSA) and the Properties of Dyes Derived from DABSA

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A single crystal of 4,4′-diaminobenzene sulfonanilide(DABSA) was determined by X-ray diffraction method. It is shown that the two benzene rings are non-planar with an angle of 55.1°. Owing to the non-planar configuration, the dyes derived from DABSA possess a lower substantivity on fiber but better permeability in substrate, the color of these azo dyes could be matched by two individual azo dyes locating on both sides of the DABSA molecule.

  13. Photosensitive soft matter: mixtures of nematic liquid crystal with azo molecules

    International Nuclear Information System (INIS)

    Photosensitive soft matter based upon guest-host liquid crystal systems was prepared by mixing azobenzene-containing mesogens with the nematic liquid crystal 4-butyl-cyclohexane carboxylic acid 4-pentyloxy-phenyl ester (CM80). Binary mixtures of the host CM80 with three azo-bonded compounds as UV-active dopants (guests) at a relatively small concentration of 1~wt.% were characterized by thermo-optical, dielectric, spectral and flexoelectric measurements. The study aimed to determine the mechanisms that result in variations of material parameters caused by light-driven molecular conformation change of the azo-dye guest molecules (the transition from rod-shaped trans isomers to bent-shaped cis isomers)

  14. Impact of Artificial Perspiration on Photo-stability of Reactive Dyes on Cellulose

    Institute of Scientific and Technical Information of China (English)

    ZHUANG De-hua; ZHANG Li-yuan; PAN Da-wei; HE Jin-xin

    2006-01-01

    The photo-reactions between metabolic products of human sweat and dyestuffs on garments may produce many toxic substances which could directly contact skin and threaten human health. In order to investigate the impact of the perspiration on photo-fading of reactive dyes on cellulose,nine commercial reactive dyes belonging to three types of chromophores (azo, Cu-complex azo and anthraquinone)respectively were chosen and their perspiration-light stability on cotton fabric was studied following ATTS test standard.It is found that the impact of the artificial perspiration on dyes varies with different chromophores: anthraquinone reactive dyes always show the best photo-stability, whereas Cu-complex azo reactive dyes appear to be the most sensitive under exposure to light and perspiration. The pH value of perspiration also greatly influences the fading of dyes with different reactive groups: the fading rate of most chlorotriazinyl reactive dyes in acidic perspiration (pH = 3.5) is higher than in alkaline perspiration (pH=8.0), while the reverse is true for most vinylsulphonyi dyes.Furthermore, the study of the contribution of individual component of the artificial perspiration discloses that LHistidine monohydrochloride monohydrate, DL-Aspartic acid and lactic acid play the major roles on the photo-fading of those selected dyestuffs and inorganic salts including disodium hydrogen phosphate and sodium chloride usually decelerate photo-fading.

  15. Characteristics of IZO/AZO and AZO/IZO Bi-layer transparent conducting thin films prepared by using PLD

    International Nuclear Information System (INIS)

    AZO/IZO and IZO/AZO bi-layer thin films were deposited on the glass substrates by using pulsed laser deposition (PLD). The crystallinity and the texture of the thin film depend on the sequence of deposition of the IZO layer and the AZO layer. The crystal structures, the electrical and optical properties of the AZO/IZO and the IZO/AZO thin film were analyzed and compared using X-ray diffraction, field-emission scanning electron microscope, Hall measurements and UV spectrometry. The IZO/AZO bi-layer thin film showed a highly-oriented texture of IZO along the axis, which implied that the c-axis-oriented AZO buffer layer enhanced the tendency of the IZO thin film to grow preferentially along the axis. On the other hand, the AZO/IZO thin film did not revealed oriented grain growth of the AZO layer, which indicated that randomly-oriented IZO buffer layer suppressed the tendency of the AZO thin film to grow preferentially along the c-axis. The AZO/IZO and the IZO/AZO bi-layer thin films showed the average values of the AZO and the IZO monolayers for the electrical resistivity and the optical band gap.

  16. Anchoring strength of o-, m-, and p-methyl red-dye-doped nematics on rubbed and unrubbed polyimide surfaces

    Science.gov (United States)

    Statman, David; Wozniak, Kaitlin; Potuzko, Marci

    2011-10-01

    It is demonstrated that the photoinduced gliding of the easy axis for nematics doped with various azo dyes on rubbed polyimide involves the formation of a second easy axis on the polyimide surface. While some azo dyes, such as disperse orange 3, do not exhibit large surface induced nonlinear effects, other dyes, such as methyl red, do. The amount of reorientation of the easy axis on rubbed polyimide is determined by the relative anchoring strengths of the easy axis formed from adsorbed dye and that formed from rubbing. One question of interest is what is the source of the anchoring strength? In this paper, we discuss the formation of easy axes via the photo-induced adsorption of azo dye. We will compare the anchoring strengths between dyed nematic liquid crystals and the easy axes formed by photoinduced adsorption of three isomers of the methyl red azo dye, ortho, meta, and para, as well as disperse orange 3. We will also discuss the impact of the carboxyl group position in the dye molecule on the anchoring strength.

  17. Preparation and Absorption Spectral Property of a Multifunctional Water-Soluble Azo Compound with D-π-A Structure, 4-(4- Hydroxy-1-Naphthylazo)Benzoic Acid

    Science.gov (United States)

    Hu, L.; Lv, H.; Xie, C. G.; Chang, W. G.; Yan, Z. Q.

    2015-07-01

    A multifunctional water-soluble azo dye with the D-π-A conjugated structure, 4-(4-hydroxy-1-naphthylazo) benzoic acid ( HNBA), was designed and synthesized using 1-naphanol as the electron donator, benzoic acid as the electron acceptor, and -N=N- as the bridging group. After its structure was characterized by FTIR, 1H NMR, and element analysis, the UV-Vis absorption spectral performance of the target dye was studied in detail. The results showed that the dye, combining hydroxyl group, azo group, and carboxyl group, possessed excellent absorption spectral properties (ɛ = 1.2·104 l·mol-1·cm-1) changing with pH and solvents. In particular, in polar and protonic water, it had excellent optical response to some metal ions, i.e., Fe3+ and Pb2+, which might make it a latent colorimetric sensor for detecting heavy metal ions.

  18. Cytotoxic and genotoxic effects of two hair dyes used in the formulation of black color.

    Science.gov (United States)

    Tafurt-Cardona, Yaliana; Suares-Rocha, Paula; Fernandes, Thaís Cristina Casimiro; Marin-Morales, Maria Aparecida

    2015-12-01

    According to the International Agency for Research on Cancer (IARC), some hair dyes are considered mutagenic and carcinogenic in in vitro assays and exposed human populations. Epidemiological studies indicate that hairdressers occupationally exposed to hair dyes have a higher risk of developing bladder cancer. In Brazil, 26% of the adults use hair dye. In this study, we investigated the toxic effects of two hair dyes, Basic Red 51 (BR51) and Basic Brown 17 (BB17), which are temporary dyes of the azo group (R-N=N-R'), used in the composition of the black hair dye. To this end, MTT and trypan blue assays (cytotoxicity), comet and micronucleus assay (genotoxicity) were applied, with HepG2 cells. For cytotoxic assessment, dyes were tested in serial dilutions, being the highest concentrations those used in the commercial formula for hair dyes. For genotoxic assessment concentrations were selected according to cell viability. Results showed that both dyes induced significant cytotoxic and genotoxic effects in the cells, in concentrations much lower than those used in the commercial formula. Genotoxic effects could be related to the azo structure present in the composition of the dyes, which is known as mutagenic and carcinogenic. These results point to the hazard of the hair dye exposure to human health. PMID:26404083

  19. Synthesis, structure and solvatochromic properties of some novel 5-arylazo-6-hydroxy-4-phenyl-3-cyano-2-pyridone dyes

    OpenAIRE

    Alimmari Adel; Mijin Dušan; Vukićević Radovan; Božić Bojan; Valentić Nataša; Vitnik Vesna; Vitnik Željko; Ušćumlić Gordana

    2012-01-01

    Abstract Background A series of some novel arylazo pyridone dyes was synthesized from the corresponding diazonium salt and 6-hydroxy-4-phenyl-3-cyano-2-pyridone using a classical reaction for the synthesis of the azo compounds. Results The structure of the dyes was confirmed by UV-vis, FT-IR, 1H NMR and 13C NMR spectroscopic techniques and elemental analysis. The solvatochromic behavior of the dyes was evaluated with respect to their visible absorption properties in various solvents. Conclusi...

  20. Transformation of Industrial Dyes by Manganese Peroxidases from Bjerkandera adusta and Pleurotus eryngii in a Manganese-Independent Reaction

    OpenAIRE

    Heinfling, A.; Martínez, M. J.; Martínez, A. T.; Bergbauer, M.; Szewzyk, U

    1998-01-01

    We investigated the transformation of six industrial azo and phthalocyanine dyes by ligninolytic peroxidases from Bjerkandera adusta and other white rot fungi. The dyes were not oxidized or were oxidized very little by Phanerochaete chrysosporium manganese peroxidase (MnP) or by a chemically generated Mn3+-lactate complex. Lignin peroxidase (LiP) from B. adusta also showed low activity with most of the dyes, but the specific activities increased 8- to 100-fold when veratryl alcohol was includ...

  1. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  2. 40 CFR 721.757 - Polyoxyalkylene substituted aromatic azo colorant.

    Science.gov (United States)

    2010-07-01

    ... azo colorant. 721.757 Section 721.757 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.757 Polyoxyalkylene substituted aromatic azo colorant. (a) Chemical... as polyoxyalkylene substituted aromatic azo colorant (PMN P-92-1131) is subject to reporting...

  3. Reduction of aromatic and heteroaromatic azo compounds with hydrazine hydrate

    Directory of Open Access Journals (Sweden)

    Sevim Rollas

    2010-01-01

    Full Text Available The azo compounds have been reduced with hydrazine hydrate in the presence of a catalyst or without a catalyst. This reaction is an atractive alternate for the reduction of azo functional group to obtain new amines. In this review, the reduction of aromatic or heteroaromatic azo compounds with hydrazine hydrate have been reported.

  4. Bioremediation of direct dyes in simulated textile effluents by a paramorphogenic form of Aspergillus oryzae.

    Science.gov (United States)

    Corso, C R; Almeida, E J R; Santos, G C; Morão, L G; Fabris, G S L; Mitter, E K

    2012-01-01

    Azo dyes are extensively used for coloring textiles, paper, food, leather, drinks, pharmaceutical products, cosmetics and inks. The textile industry consumes the largest amount of azo dyes, and it is estimated that approximately 10-15% of dyes used for coloring textiles may be lost in waste streams. Almost all azo dyes are synthetic and resist biodegradation, however, they can readily be reduced by a number of chemical and biological reducing systems. Biological treatment has advantages over physical and chemical methods due to lower costs and minimal environmental effect. This research focuses on the utilization of Aspergillus oryzae to remove some types of azo dyes from aqueous solutions. The fungus, physically induced in its paramorphogenic form (called 'pellets'), was used in the dye biosorption studies with both non-autoclaved and autoclaved hyphae, at different pH values. The goals were the removal of dyes by biosorption and the decrease of their toxicity. The dyes used were Direct Red 23 and Direct Violet 51. Their spectral stability (325-700 nm) was analyzed at different pH values (2.50, 4.50 and 6.50). The best biosorptive pH value and the toxicity limit, (which is given by the lethal concentration (LC(100)), were then determined. Each dye showed the same spectrum at different pH values. The best biosorptive pH was 2.50, for both non- autoclaved and autoclaved hyphae of A. oryzae. The toxicity level of the dyes was determined using the Trimmed Spearman-Karber Method, with Daphnia similis in all bioassays. The Direct Violet 51 (LC(100) 400 mg · mL(-1)) was found to be the most toxic dye, followed by the Direct Red 23 (LC(100) 900 mg · mL(-1)). The toxicity bioassays for each dye have shown that it is possible to decrease the toxicity level to zero by adding a small quantity of biomass from A. oryzae in its paramorphogenic form. The autoclaved biomass had a higher biosorptive capacity for the dye than the non-autoclaved biomass. The results show that

  5. Synthesis of two new azo-azomethines; spectral characterization, crystal structures, computational and fluorescence studies

    Science.gov (United States)

    Eskikanbur, Sevgi; Sayin, Koray; Kose, Muhammet; Zengin, Huseyin; McKee, Vickie; Kurtoglu, Mukerrem

    2015-08-01

    This study describes the preparation, characterization and the photoluminescence properties of novel azo-azomethines (2-{(E)-[(4-ethylphenyl)imino]methyl}-4-[(E)-phenyldiazenyl]phenol, HL1 and 2-{(E)-[(3-ethylphenyl)imino]methyl}-4-[(E)-phenyldiazenyl]phenol, HL2 dyes). The dyes were characterized by elemental analysis, spectroscopic studies such as IR, 1H and 13C NMR, mass and fluorescence spectra. Molecular structures of the dyes were examined by X-ray diffraction analysis. The molecular structures are mostly similar, differing mainly in the position of the ethyl group and dihedral angles between aromatic rings. X-ray data revealed that both HL1 and HL2 favor phenol-imine tautomer in the solid state. An intramolecular phenol-imine hydrogen bond (O1⋯N1) were observed in both compounds resulting in a S(6) hydrogen bonding motif. Molecular packing of both compounds are determined by π⋯π interactions. Quantum chemical investigation of mentioned molecules were performed by using DFT hybrid function (B3LYP) with 6-31+G(d) basis set. The compounds HL1 and HL1 gave intense light emissions upon irradiation by Ultra-Violet light. The photoluminescence quantum yields and long excited-state lifetimes of the compounds HL1 and HL2 were measured. The azo-azomethine dyes HL1 and HL2 have photoluminescence quantum yields of 34% and 32% and excited-state lifetimes of 3.21 and 2.98 ns, respectively. The photoluminescence intensities and quantum yields of these dyes were dependent on the position of alkyl group on the phenyl ring.

  6. Synthesis and application of novel heterocyclic dyes based on 11-amino-13H-acenaphtho[1,2-e]pyridazino[3,2-b]quinazolin-13-one

    Directory of Open Access Journals (Sweden)

    RANJAN G. PATEL

    2002-11-01

    Full Text Available A new fused heterocyclic compound, 11-amino-13H-acenaphtho[1,2-e]pyridazino [3,2-b]quinazolin-13-one was synthesized and used to prepare a novel series of heterocyclic mono azo dyes by coupling with various naphthols. All the mono azo dyes were characterized by their melting point, elemental analysis,UV-visible spectrum, infrared spectrum and dyeing performance on nylon and polyester fibres. The percentage dye bath exhaustion on different fibres was found to be reasonably good and acceptable. The dyed fibres show fair to good fastness to light and very good to excellent fastness to washing, rubbing, perspiration and sublimation.

  7. Mechanism of azo coupling. II. Dual reactivity of aromatic amines in azo coupling

    International Nuclear Information System (INIS)

    On the basis of the method perturbations of molecular orbitals and of the kinetics of azo coupling in polar aprotic media in presence of alkylammonium chlorides it was shown that the positional selectivity of primary, secondary, and tertiary amines in azo coupling is determined both by the activities of the reaction centers of the substrate, and also by the ease with which the intermediate (aryldiazo)ammonium ion and sigma/sub C/ complex are converted into the final diazoamino and amino azo compounds

  8. Synthesis and dyeing properties of new disazo disperse dyes for polyester and nylon fabrics

    Directory of Open Access Journals (Sweden)

    Tarulata B. Shah

    2014-12-01

    Full Text Available Diazotized aryl amines were coupled with two stenhouse salt namely, N-(5-phenylamino-penta-4-ol-2,4-diene-1-ylideneanilines hydrochloride [S1 (RH or S2 (ROH] to furnish two series of disazo disperse dyes (S1D1–10 and S2D1–10. The structure of all the dyes was established by estimating number of azo groups, elemental analysis and spectral studies (IR, 1H-NMR, UV/Visible. The structure–property relationship was discussed by using electronic absorption spectra of the dyes. These dyes were applied to polyester and nylon fabrics as disperse dyes by using temperature exhaust dyeing method. The relevant dyeing characteristics, such as dyeability on fabrics, wash-fastness and light-fastness were evaluated. Fabrics dyed with these dyes furnished generally deep and bright intense hues ranging from light yellow to orange to reddish brown. The color fastness of the dyed fabric was assessed by determining wash-fastness and light-fastness properties.

  9. Identification and molecular characterization of a novel flavin-free NADPH preferred azoreductase encoded by azoB in Pigmentiphaga kullae K24

    Directory of Open Access Journals (Sweden)

    Xu Haiyan

    2010-03-01

    Full Text Available Abstract Background Microbial degradation of azo dyes is commonly initiated by the reduction of the azo bond(s by a group of NADH or NADPH dependant azoreductases with many requiring flavin as a cofactor. In this study, we report the identification of a novel flavin-free NADPH preferred azoreductase encoded by azoB in Pigmentiphaga kullae K24. Results The deduced amino acid sequence of azoB from P. kullae K24 showed 61% identity to a previously studied azoreductase (AzoA from the same strain. azoB encoded a protein of 203 amino acids and heterologously expressed in Escherichia coli. The purified recombinant enzyme was a monomer with a molecular mass of 22 kDa. Both NADH and NADPH can be used as an electron donor for its activity with 4-(4-hydroxy-1-naphthylazo benzenesulfonic acid (Orange I as substrate. The apparent Km values for both NADH and Orange I were 170 and 8.6 μM, respectively. The Km of NADPH for the enzyme is 1.0 μM. When NADPH served as the electron donor, the activity of the enzyme is 63% higher than that when NADH was used. The pH and temperature optima for activity of the enzyme with Orange I as the substrate were at pH 6.0 and between 37 and 45°C. Phylogenetic analysis shows that AzoB belongs to the flavin-free azoreductase group which has a key fingerprint motif GXXGXXG for NAD(PH binding at the N-terminus of the amino acid sequences. The 3D structure of AzoB was generated by comparative modeling approach. The structural combination of three conserved glycine residues (G7xxG10xxG13 in the pyrophosphate-binding loop with the Arg-32 explains the preference for NADPH of AzoB. Conclusion The biochemical and structural properties of AzoB from P. kullae K24 revealed its preference for NADPH over NADH and it is a member of the monomeric flavin-free azoreductase group. Our studies show the substrate specificity of AzoB based on structure and cofactor requirement and the phylogenetic relationship among azoreductase groups.

  10. Adsorption of a Textile Dye on Commercial Activated Carbon: A Simple Experiment to Explore the Role of Surface Chemistry and Ionic Strength

    Science.gov (United States)

    Martins, Angela; Nunes, Nelson

    2015-01-01

    In this study, an adsorption experiment is proposed using commercial activated carbon as adsorbent and a textile azo dye, Mordant Blue-9, as adsorbate. The surface chemistry of the activated carbon is changed through a simple oxidation treatment and the ionic strength of the dye solution is also modified, simulating distinct conditions of water…

  11. Degradation of environment pollutant dyes using phytosynthesized metal nanocatalysts

    Science.gov (United States)

    MeenaKumari, M.; Philip, Daizy

    2015-01-01

    We present for the first time biogenic reduction and stabilization of gold and silver ions at room temperature using fruit juice of Punica granatum. The formation, morphology and crystalline structure of the synthesized nanoparticles are determined using UV-Visible, XRD and TEM. An attempt to reveal the partial role of phenolic hydroxyls in the reduction of Au3+ and Ag+ is done through FTIR analysis. The synthesized nanoparticles are used as potential catalysts in the degradation of a cationic phenothiazine dye, an anionic mono azo dye and a cationic fluorescent dye. The calculated values of percentage removal of dyes and the rate constants from pseudo first order kinetic data fit give a comparative study on degradation of organic dyes in presence of prepared gold and silver nanoparticles.

  12. Genetic Damage Induced by a Food Coloring Dye (Sunset Yellow on Meristematic Cells of Brassica campestris L.

    Directory of Open Access Journals (Sweden)

    Kshama Dwivedi

    2015-01-01

    Full Text Available We have performed the present piece of work to evaluate the effect of synthetic food coloring azo dye (sunset yellow on actively dividing root tip cells of Brassica campestris L. Three doses of azo dye were administered for the treatment of actively dividing root tip cells, namely, 1%, 3%, and 5%, for 6-hour duration along with control. Mitotic analysis clearly revealed the azo dye induced endpoint deviation like reduction in the frequency of normal divisions in a dose dependent manner. Mitotic divisions in the control sets were found to be perfectly normal while dose based reduction in MI was registered in the treated sets. Azo dye has induced several chromosomal aberrations (genotoxic effect at various stages of cell cycle such as stickiness of chromosomes, micronuclei formation, precocious migration of chromosome, unorientation, forward movement of chromosome, laggards, and chromatin bridge. Among all, stickiness of chromosomes was present in the highest frequency followed by partial genome elimination as micronuclei. The present study suggests that extensive use of synthetic dye should be forbidden due to genotoxic and cytotoxic impacts on living cells. Thus, there is an urgent need to assess potential hazardous effects of these dyes on other test systems like human and nonhuman biota for better scrutiny.

  13. Optimization of Biosorptive Removal of Dye from Aqueous System by Cone Shell of Calabrian Pine

    OpenAIRE

    Fatih Deniz

    2014-01-01

    The biosorption performance of raw cone shell of Calabrian pine for C.I. Basic Red 46 as a model azo dye from aqueous system was optimized using Taguchi experimental design methodology. L9 (33) orthogonal array was used to optimize the dye biosorption by the pine cone shell. The selected factors and their levels were biosorbent particle size, dye concentration, and contact time. The predicted dye biosorption capacity for the pine cone shell from Taguchi design was obtained as 71.770 mg g−1 un...

  14. Decolourisation of Synthetic Dyes by Endophytic Fungal Flora Isolated from Senduduk Plant (Melastoma malabathricum)

    OpenAIRE

    Ahmad Husaini; Hairul Azman Roslan; Ngui Sing Ngieng; Azham Zulkharnain

    2013-01-01

    A total of twenty endophytic fungi successfully isolated from Melastoma malabathricum (Senduduk) were examined for their ability to decolourise azo dyes: Congo red, Orange G, and Methyl red and an anthraquinone dye, Remazol Brilliant Blue R. Initial screening on the glucose minimal media agar plates amended with 200 mg L−1 of each respective dye showed that only isolate MS8 was able to decolourise all of the four dyes. The isolate decolourised completely both the RBBR and Orange G in the agar...

  15. Biodegradation of Textile Dyes by Fungi Isolated from North Indian Field Soil

    OpenAIRE

    Arshi Shahid; Jagvijay Singh; Sandeep Bisht; Priyanku Teotia; Vivek Kumar

    2013-01-01

    In this study one azo dye "Congo red", two triphenymethane dyes "Crystal violet" and "Methylene blue" have been selected for biodegradation using three soil fungal isolates A. niger, F. oxysporum and T. lignorum. These fungal strains were isolated from field soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25°C. The experiment was conducted for 10 days and the results were periodically observed. Aspergillus ...

  16. Study of Modern Nano Enhanced Techniques for Removal of Dyes and Metals

    OpenAIRE

    2014-01-01

    Industrial effluent often contains the significant amount of hexavalent chromium and synthetic dyes. The discharge of wastewater without proper treatment into water streams consequently enters the soil and disturbs the aquatic and terrestrial life. A range of wastewater treatment technologies have been proposed which can efficiently reduce both Cr(VI) and azo dyes simultaneously to less toxic form such as biodegradation, biosorption, adsorption, bioaccumulation, and nanotechnology. Rate of si...

  17. Polymers and Dyes: Developments and Applications

    Directory of Open Access Journals (Sweden)

    Carolin Fleischmann

    2015-04-01

    Full Text Available Amongst functional macromolecules, the combination of polymers and dyes is a research field of great potential with regard to high-performance materials. Accordingly, colored polymers have become increasingly important as materials for miscellaneous technical applications in recent years while also being a major part of everyday life. For instance, dye-containing polymers are nowadays widely applied in medicine, painting industries, analytics and gas separation processes. Since these applications are obviously connected to the dye’s nature, which is incorporated into the corresponding polymers, the affinity of certain polymers to dyes is exploited in wastewater work-ups after (textile dyeing procedures. In this review, we wish to point out the great importance of dye-containing polymers, with a comprehensive scope and a focus on azo, triphenylmethane, indigoid, perylene and anthraquinone dyes. Since a large number of synthetic approaches towards the preparation of such materials can be found in the literature, an elaborated overview of different preparation techniques is given as well.

  18. Photocatalytical Elimination of Industrial Dyes in Wastewater

    Czech Academy of Sciences Publication Activity Database

    Morozová, Magdalena; Klusoň, Petr; Matějková, Martina; Šnajdaufová, Hana; Šolcová, Olga

    Thessaloniki : Grafima Publ, 2014 - (Liakopoulos, A.; Kungolos, A.; Christodoulatos, C.; Koutsospyros, A.), s. 43 ISBN 978-960-88490-5-1. [International Conference on Protection and Restoration of the Environment /12./. Skiathos island (GR), 29.06.2014-03.07.2014] R&D Projects: GA TA ČR TA01020804; GA TA ČR TA03010548 Grant ostatní: NATO(US) SPS984398 Institutional support: RVO:67985858 Keywords : titanium dioxide * azo dye * water purification Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  19. Comments on “Spectroscopic studies of keto–enol tautomeric equilibrium of azo dyes” by M. A. Rauf, S. Hisaindee and N. Saleh, published in RSC Advances 2015, 5, 18097-18110 as a Review Article

    DEFF Research Database (Denmark)

    Antonov, Liudmil; Hansen, Poul Erik; van der Zwan, Gert

    2015-01-01

    The paper mentioned in the title contains inaccuracies and misleading interpretations that seriously misrepresent basic knowledge about tautomerism in azo dyes. Therefore, we aim in this Letter to correct the most obvious mistakes, to address the misrepresentation of the main issues of tautomerism...

  20. Azo coupling of 4-nitrophenyldiazonium chloride with aliphatic nucleophiles: an integrated organic synthesis and X-ray crystallography experiment

    International Nuclear Information System (INIS)

    This article describes an undergraduate experiment for the synthesis of p-nitrophenyldiazonium chloride and its coupling with acetylacetone and two enaminones, 4-phenylamino-pent-3-en-2-one and 4-amino-pent-3-en-2-one, in an adaptation of a previously reported synthetic protocol. The azo dyes 4-(E)-phenylamino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one and 4-(E)-amino-3-[(E)-2-(4-nitrophenylazo)]-3-penten-2-one were obtained, and the solid state structure of this latter azo compound was characterized by single crystal X-ray diffraction studies. This two-week integrated laboratory approach involves simple synthetic experiments and microwave chemistry in the organic laboratory plus crystallography analysis, suitable for novice students on undergraduate experimental chemistry courses. (author)

  1. Azo-derivatives thin films grown by matrix-assisted pulsed laser evaporation for non-linear optical applications

    International Nuclear Information System (INIS)

    Azo-dye compounds, in bulk or as thin films, are extensively studied due to their particular optical properties. These properties include non-linear interaction, e.g. two-photon absorption, optical limiting and all-optical poling, with potential applications in optoelectronics and sensors development. Herein, we report on the deposition of pyrazolone derivatives, namely 1-phenyl-3-methyl-4-(1′-azo-2′-sodium carboxylate)-pyrazole-5-one thin films, for applications in second harmonic generation. Matrix-assisted pulsed laser evaporation was employed for layers growth, using a Nd:YAG device operating at 266 nm (4ω). The structure and surface morphology of the deposited films were examined by Fourier transform infrared spectroscopy, atomic force microscopy, and scanning electron microscopy. Spectroscopic-ellipsometry was employed to investigate thin film optical properties. Significant second harmonic generation capabilities of the compound were pointed out by using a femtosecond Ti:sapphire laser.

  2. Studies on Synthesis and Dyeing Preformance of Acid Dyes Based on 4,7-Dihydroxy-1,10-Phenanthroline-2,9-Dione

    OpenAIRE

    Patel, B. V.; Dasondi, P. H.

    2008-01-01

    Some new azo acid dyes were prepared by coupling various diazotized acid components such as anthranilic acid, sulphanilic acid, laurent acid, peri acid, tobias acid, H-acid, J-acid, gamma acid, sulphotobias acid, 4-aminotoluiene-3-sulphonic acid, 5-sulpho- anthranilic acid, 2-naphthylamine-3,6,8-trisulphonic acid, bronner acid, metanilic acid and cleve acid with 4,7-dihydroxy-1,10-phenanthroline-2,9-dione. The dyes were characterized by elemental, IR and TLC analyses. Their dyeing performance...

  3. The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

    International Nuclear Information System (INIS)

    A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10−3 Ω−1 with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10−3 Ω−1 with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure

  4. The structural and electro-optical characteristics of AZO/Cr:Cu/AZO transparent conductive film

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Tien-Chai [Department of Electrical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Huang, Wen-Chang, E-mail: wchuang@mail.ksu.edu.tw [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China); Tsai, Fu-Chun [Department of Electro-Optical Engineering, Kun Shan University, No. 195, Kun-Da Road, Yung-Kang Dist., Tainan 71003, Taiwan, ROC (China)

    2015-08-31

    A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO (ACCA), was presented in the paper. The structural and electro-optical properties of the ACCA film were discussed. The thickness of the middle metal layer was constant and those of the AZO layers were varied. The ACCA film shows an obvious ZnO (002) c-axis preferential growth. No diffraction peaks related to Cr and Cu were observed through x-ray diffraction analysis. The middle Cr:Cu layer showed a thickness of 8.16 nm with a continuous and amorphous structure by the observation of a high-resolution transmission electron microscopy (HR-TEM). For the electro-optical characteristic, a best figure of merit (FOM) value of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85% was obtained at the thickness of 116 nm of ACCA film. The high FOM value of the film is due to the improvement of conductivity and small sacrifices of transparency. - Highlights: • A novel triple-layered transparent conductive film, AZO/Cr:Cu/AZO is developed. • Chromium is added to copper to reduce the oxidation–reduction reaction. • The film has a FOM of 3.54 × 10{sup −3} Ω{sup −1} with a corresponding transmittance of 85%. • The Cr:Cu layer shows a continuous and amorphous structure.

  5. Preparation of azo compounds with solid catalysts

    OpenAIRE

    Corma, Avelino; García Gómez, Hermenegildo; Grirrane, Abdessamad

    2008-01-01

    [EN] The present invention refers to a procedure for preparing azo compounds comprising a reaction between at least: one amine or polyamine, molecular oxygen, a catalyst comprising at least one support selected fkom at least a metal oxide of one of the elements of the groups 3,4, 5, 6, 8, 9, 11 and 13, silica, an anionic laminar compound of hydrotalcite type or its derivatives, active carbon or an organic polymer. In addition, said catalyst may contain nanoparticles of gold.

  6. Effects of Controlling the AZO Thin Film's Optical Band Gap on AZO/MEH-PPV Devices with Buffer Layer

    OpenAIRE

    Jaehyoung Park; Ki-Chang Jung; Ari Lee; Hyojung Bae; Daehwa Mun; Jun-Seok Ha; Young-Bu Mun; Han, E. M.; Hang-Ju Ko

    2012-01-01

    Organic/inorganic hybrid solar cells were fabricated incorporating aluminum-doped zinc oxide (AZO) thin films of varying optical band gap in AZO/poly(2-methoxy-5-(2′-ethyl-hexyloxy)-p-phenylene vinylene) structures. The band gaps were controlled by varying the flow rates of Ar and O2 used to deposit the AZO. Devices with CdS buffer layer were also fabricated for improved efficiency. The effects of AZO optical band gap were assessed by testing the I–V characteristics of devices with structures...

  7. Degradation of Reactive Black 5 dye by a newly isolated bacterium Pseudomonas entomophila BS1.

    Science.gov (United States)

    Khan, Sana; Malik, Abdul

    2016-03-01

    The textile and dye industries are considered as one of the major sources of environmental pollution. The present study was conducted to investigate the degradation of the azo dye Reactive Black 5 (RB 5) using a bacterium isolated from soil samples collected around a textile industry. The bacterial strain BS1 capable of degrading RB 5 was isolated and identified as Pseudomonas entomophila on the basis of 16S rDNA sequencing. The effects of different parameters on the degradation of RB 5 were studied to find out the optimal conditions required for maximum degradation, which was 93% after 120 h of incubation. Static conditions with pH in the range of 5-9 and a temperature of 37 °C were found to be optimum for degrading RB 5. Enzyme assays demonstrated that P. entomophila possessed azoreductase, which played an important role in degradation. The enzyme was dependent on flavin mononucleotide and NADH for its activity. Furthermore, a possible degradation pathway of the dye was proposed through gas chromatography - mass spectrometry analysis, which revealed that the metabolic products were naphthalene-1,2-diamine and 4-(methylsulfonyl) aniline. Thus the ability of this indigenous bacterial isolate for simultaneous decolorization and degradation of the azo dye signifies its potential application for treatment of industrial wastewaters containing azo dyes. PMID:26911309

  8. Isolation and Screening of Water Microbes for Decolourisation of Textile Dye Waste

    Directory of Open Access Journals (Sweden)

    J. K. Singh,

    2016-04-01

    Full Text Available Azo dyes are widely used in textile industry. Unused dyes, consisting mainly non biodegradable released along with waste water streams without any proper pre-treatment which cause nuisance for environment and accumulate in flora as well as fauna. These also exhibit allergic, carcinogenic and mutagenic properties for human beings. Isolation and screening of azo dye degrading bacteria are economic in biodegradation and detoxification. In the present study, 200 waste water samples were collected from dye-contaminated sites of textile industries and bacterial species such as Bacillus subtilis, Pseudomonas aeruginosa and Psuedomonas putida were isolated and identified. Evaluation of decolorizing properties of these bacteriae were done by UV-Vis spectroscopy (Amax 596 nm in different concentrations using different carbon sources such as Hans’s medium and GYP medium. Maximum decolourisation of 0.1% azo dyes were recorded to be 89.0%, 91% and 86% in Hans medium containing charcoal source by Bacillus subtilis, Pseudomonas aeruginosa and Psuedomonas putida respectively at 24 hrs. These bacterial isolates may be utilized in large scale for pre-treatment for ecological balance by avoiding water pollution.

  9. Biodegradation of Navy N5RL1 carpet dye by Staphylococcus saprophyticus strain BHUSS X3

    OpenAIRE

    Kumari, Lata; Verma, Ajay Kumar; Tiwary, Dhanesh; Giri, Deen Dayal; Nath, Gopal; Mishra, Pradeep Kumar

    2015-01-01

    Biodegradation of Navy N5RL1, a widely used acidic azo dye in carpet industry, was studied by bacterial strain isolated from the dye-contaminated soil collected from a carpet industry premises located in Bhadohi, Sant Ravidas Nagar and Uttar Pradesh, India. The isolated strain was identified as Staphylococcus saprophyticus BHUSS X3 on the basis of morphological, biochemical and 16S rRNA gene sequencing analysis. The strain BHUSS X3 decolorized 95.7 % of dye (100 mg/l) within 6 h at optimum pH...

  10. Experimental and ab initio DFT calculated Raman Spectrum of Sudan I, a Red Dye

    DEFF Research Database (Denmark)

    Kunov-Kruse, Andreas Jonas; Kristensen, Steffen Buus; Liu, Chuan;

    2011-01-01

    . Comparison was made with other azo dyes in the literature on natural, abundant plant pigments. The results show that there is a possibility in foodstuff analysis to distinguish Sudan I from other dyes by using Raman spectroscopy with more than one laser wavelength for resonance enhancement of the different......The red dye Sudan I was investigated by Raman spectroscopy using different excitation wavelengths (1064, 532 and 244 nm). A calculation of the Raman spectrum based on quantum mechanical ab initio density functional theory (DFT) was made using the RB3LYP method with the 3-21G and 6-311+G(d,p) basis...

  11. Dye detoxification by Lentinula edodes INCQS 40220 | Detoxificação de corante por Lentinula edodes INCQS 40220

    OpenAIRE

    Ludmila R. Bergsten-Torralba; Helena P. S. Zamith; Taline Ramos Conde; Aiub, Claudia A. F.; Israel Felzenszwalb; Manuela da Silva

    2016-01-01

    Lentinula edodes belongs to the group of fungi known as ligninolytic fungi, due to its ability to degrade the aromatic structure of the lignin. Textile dyes also have aromatic structure, and after microbial degradation, some of them can be transformed into toxic compounds, when compared to the original structure, representing risk to environment and human health. Therefore, the potential of the fungus L. edodes INCQS 40220 to decolorize and to detoxify reactive red 198 (azo dye), reactive blu...

  12. Degradation of a monoazo dye Alizarin Yellow GG in aqueous solutions by gamma irradiation: Decolorization and biodegradability enhancement

    Science.gov (United States)

    Sun, Weihua; Chen, Lujun; Tian, Jinping; Wang, Jianlong; He, Shijun

    2013-02-01

    The irradiation-induced degradation of an azo dye, Alizarin Yellow GG (AY-GG), was investigated in aqueous solution under gamma irradiation using a 60Cobalt source at a dose rate of 113 Gy/min. The decolorization percentage of AY-GG reached 65% when its initial concentration was 100 mg/l and the absorbed dose was 9 kGy. The decolorization process could be described by first-order kinetic equation. In addition, specific oxygen uptake rate (SOUR, mg O2 (g MLVSS)-1 h-1) of activated sludge using the irradiated azo dye solutions was 8.1 mg O2 (g MLVSS)-1 h-1 after 9 kGy irradiation, indicating that the biodegradability of AY-GG could be enhanced by 30%. However, toxic intermediates including heterocyclic aromatic amines and cyanides were detected during the irradiation process, which inhibited the complete biological degradation of azo dye. Fortunately, the inhibition could be eliminated by further irradiation. The azo dye solution became amenable to biodegradation and can be further treated by biological treatment process.

  13. Reduction of aromatic and heteroaromatic azo compounds with hydrazine hydrate

    OpenAIRE

    Sevim Rollas

    2010-01-01

    ABSTRACT: The azo compounds have been reduced with hydrazine hydrate in the presenceof a catalyst or without a catalyst. This reaction is an atractive alternate for the reduction ofazo functional group to obtain new amines. In this review, the reduction of aromatic or heteroaromaticazo compounds with hydrazine hydrate have been reported.KEYWORDS: Reduction, azo compounds, uncatalyzed reduction, hydrazine hydrate.

  14. Mycoremediation of Congo red dye by filamentous fungi

    Directory of Open Access Journals (Sweden)

    Sourav Bhattacharya

    2011-12-01

    Full Text Available Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was to study the factors influencing mycoremediation of Congo red. Several basidiomycetes and deuteromycetes species were tested for the decolourisation of Congo red (0.05 g/l in a semi synthetic broth at static and shaking conditions. Poor decolourisation was observed when the dye acted as the sole source of nitrogen, whereas semi synthetic broth supplemented with fertilizer resulted in better decolourisation. Decolourisation of Congo red was checked in the presence of salts of heavy metals such as mercuric chloride, lead acetate and zinc sulphate. Decolourisation parameters such as temperature, pH, and rpm were optimized and the decolourisation obtained at optimized conditions varied between 29.25- 97.28% at static condition and 82.1- 100% at shaking condition. Sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis revealed bands with molecular weights ranging between 66.5 to 71 kDa, a characteristic of the fungal laccases. High efficiency decolourisation of Congo red makes these fungal forms a promising choice in biological treatment of waste water containing Congo red.

  15. Thermal durability of AZO/Ag(Al)/AZO transparent conductive films

    Science.gov (United States)

    Sugimoto, Yukiko; Igarashi, Kanae; Shirasaki, Shinya; Kikuchi, Akihiko

    2016-04-01

    Effects of Al doping on surface morphology, sheet resistance, optical transmission spectra, and thermal durability of a thin Ag layer and AZO/Ag/AZO dielectric/metal/dielectric (DMD) transparent conductive films (TCFs) were investigated. The 1.7 at. % Al doping suppressed the initial island growth of a thin Ag layer and the plasmon resonant absorption dip in the optical transmission spectra. The threshold thickness of percolation conductivity was reduced from 9-10 (pure Al layer) to 5-6 nm (1.7 at. % Al-doped Ag layer). Al doping in the Ag layer improved the thermal durability of AZO/Ag/AZO-DMD TCFs. The threshold temperature for Ag void formation increased from 400 °C (DMD with pure Ag layer) to 600 °C (DMD with a 10.5 at. % Al-doped Ag layer). The optimum annealing temperature increased from 300 °C (DMD with a pure Ag layer) to 500 °C (DMD with a 10.5 at. % Al-doped Ag layer). Maximum figures of merit (FOM) were 0.5 × 10-2 and 1.1 × 10-2 Ω-1 for the DMD with a pure Ag layer and that with a 10.5 at. % Al-doped Ag layer, respectively.

  16. trans/cis-Isomerization of fluorene-bridged azo chromophore with significant two-photon absorbability at near-infrared wavelength.

    Science.gov (United States)

    Chu, Chih-Chien; Chang, Ya-Chi; Tsai, Bo-Kai; Lin, Tzu-Chau; Lin, Ja-Hon; Hsiao, Vincent K S

    2014-12-01

    Azo-containing materials have been proven to possess second-order nonlinear optical (NLO) properties, but their third-order NLO properties, which involves two-photon absorption (2PA), has rarely been reported. In this study, we demonstrate a significant 2PA behavior of the novel azo chromophore incorporated with bilateral diphenylaminofluorenes (DPAFs) as a π framework. The electron-donating DPAF moieties cause a redshifted π-π* absorption band centered at 470 nm, thus allowing efficient blue-light-induced trans-to-cis photoisomerization with a rate constant of 2.04 × 10(-1) min(-1) at the photostationary state (PSS). The open-aperture Z-scan technique that adopted a femtosecond (fs) pulse laser as excitation source shows an appreciably higher 2PA cross-section for the fluorene-derived azo chromophore than that for common azobenzene dyes at near-infrared wavelength (λex =800 nm). Furthermore, the fs 2PA response is quite uniform regardless of the molecular geometry. On the basis of the computational modeling, the intramolecular charge-transfer (ICT) process from peripheral diphenylamines to the central azo group through a fluorene π bridge is crucial to this remarkable 2PA behavior. PMID:25294108

  17. New azo coupling reactions for visible spectrophotometric determination of salbutamol in bulk and pharmaceutical preparations

    International Nuclear Information System (INIS)

    The purpose of the present study was to develop a new, simple, cheap, fast, accurate, and sensitive colorimetric methods that can be used for the determination of salbutamol sulphate drug in pure from as well as in pharmaceutical formulations. The method is based on the reaction 2-chloro-4-nitroaniline with nitrite in acid medium to form diazonium ion, which is coupled with of salbutamol in basic medium to form azo dyes, showing yellow color and absorption maxima at 463 nm. Beer's law is obeyed in the concentration of 4-48μg/ml. The molar absorptivity and san dell's sensitivity are 5.27x103 L mole-1 cm-1, 0.015 μgcm-2, respectively. The optimum reaction conditions and other analytical parameters were evaluated. (author).

  18. 40 CFR 721.10108 - Naphthalenedisulfonic acid, hydrozy-[[[(hydroxyl-disulfo-naphthaleneyl)azo]-alkyl(C=1-5...

    Science.gov (United States)

    2010-07-01

    ...- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). 721.10108 Section 721... Naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted azo-, metal salt (generic). (a... generically as naphthalenedisulfonic acid, hydrozy- -alkyl(C=1-5)-(sulfoalkoxy)cyclic]azo]-substituted...

  19. Preparation and morphological and optical characterization of azo-polymer-based SiO2 sonogel hybrid composites

    International Nuclear Information System (INIS)

    The well-established catalyst-free sonogel route was successfully implemented to fabricate highly pure, optically active, solid state polymeric azo- dye/SiO2-based hybrid composites. Bulk samples exhibit controllable geometrical shapes and monolithic structure with variable dopant concentrations. Since the implemented azo-dye chromophores exhibit a push–pull structure, hybrid film samples were spin-coated on ITO-covered glass substrates; molecular alignment was then performed via electrical poling in order to explore the quadratic nonlinear optical performance of this kind of composite. Comprehensive morphological, spectroscopic and optical characterization of the samples were performed with several experimental techniques: atomic force microscopy, x-ray diffraction and infrared, Raman, photoluminescent and ultraviolet–visible spectroscopies. The linear refractive indices of both bulk and thin film samples were measured according to the Brewster angle technique and a numerical analysis of the transmission spectral data, respectively. Regardless of the low glass transition temperatures of the studied polymers, some hybrid film samples were able to display stable nonlinear optical activity such as second harmonic generation. Results show that the chromophores were satisfactorily embedded into the highly pure SiO2 sonogel network without significant guest–host molecular interactions, thus preserving their optical properties and producing sol gel hybrid glasses suitable for optical applications

  20. Quantitative structure-activity relationship analysis of substituted arylazo pyridone dyes in photocatalytic system: Experimental and theoretical study.

    Science.gov (United States)

    Dostanić, J; Lončarević, D; Zlatar, M; Vlahović, F; Jovanović, D M

    2016-10-01

    A series of arylazo pyridone dyes was synthesized by changing the type of the substituent group in the diazo moiety, ranging from strong electron-donating to strong electron-withdrawing groups. The structural and electronic properties of the investigated dyes was calculated at the M062X/6-31+G(d,p) level of theory. The observed good linear correlations between atomic charges and Hammett σp constants provided a basis to discuss the transmission of electronic substituent effects through a dye framework. The reactivity of synthesized dyes was tested through their decolorization efficiency in TiO2 photocatalytic system (Degussa P-25). Quantitative structure-activity relationship analysis revealed a strong correlation between reactivity of investigated dyes and Hammett substituent constants. The reaction was facilitated by electron-withdrawing groups, and retarded by electron-donating ones. Quantum mechanical calculations was used in order to describe the mechanism of the photocatalytic oxidation reactions of investigated dyes and interpret their reactivities within the framework of the Density Functional Theory (DFT). According to DFT based reactivity descriptors, i.e. Fukui functions and local softness, the active site moves from azo nitrogen atom linked to benzene ring to pyridone carbon atom linked to azo bond, going from dyes with electron-donating groups to dyes with electron-withdrawing groups. PMID:27209516

  1. 40 CFR 721.5281 - 2-Naphthalenesulfonic acid, 3-[[4-[(2,4-dimethyl-6-sulfophenyl)azo]-2-methoxy-5-methylphenyl]azo...

    Science.gov (United States)

    2010-07-01

    ...-methoxy-5-methylphenyl]azo]-4-hydroxy-7-(phenylamino)-, sodium salt, compd. With 2,2â²,2â³-nitrilotris... Specific Chemical Substances § 721.5281 2-Naphthalenesulfonic acid, 3- -2-methoxy-5-methylphenyl]azo]-4..., 3- -2-methoxy-5-methylphenyl]azo]-4-hydroxy-7-(phenylamino)-, sodium salt, compd. With...

  2. Preparation and Photo-thermal Isomerization of Azo [2.2.1]-and Azo[2.2.3]metacyclophane Tweezers

    OpenAIRE

    Sawada, Tsuyoshi; Thiemann, Thies; Mataka, Shuntaro

    1999-01-01

    Azo[2.2.1]metacyclophane (MCP) tweezer 11 and azo[2.2.3]MCP tweezer 12 were prepared from [2.2.1]MCP 1a and [2.2.3]MCP 8, respectively, by ipso-nitration followed by reductive coupling using LiAlH_4. The photochemical and thermal isomerization of azo[2.2.n]MCP tweezers were studied by UV spectroscopy. The activation parameter (E_a) of the thermal cis-trans isomerization of 11 and 12 was determined as 81.7 kJmol^ and 90.9 kJmol^, respectively.

  3. Nano-dyeing

    Directory of Open Access Journals (Sweden)

    Ning Cui-Juan

    2016-01-01

    Full Text Available Dyeing nanofibers is a frontier of both modern textile engineering and nanotechnology. This paper suggest a feasible method for dyeing nanofibers with a natural red (Roselle Calyx by bubble electrospinning. Reactive dye (Red S3B and acid dye (Red 2B were also used in the experiment for comparison. The dyeing process was finished during the spinning process.

  4. Biodecolorization of recalcitrant dye as the sole sourceof nutrition using Curvularia clavata NZ2 and decolorization ability of its crude enzymes.

    Science.gov (United States)

    Neoh, Chin Hong; Lam, Chi Yong; Lim, Chi Kim; Yahya, Adibah; Bay, Hui Han; Ibrahim, Zaharah; Noor, Zainura Zainon

    2015-08-01

    Extensive use of recalcitrant azo dyes in textile and paper industries poses a direct threat to the environment due to the carcinogenicity of their degradation products. The aim of this study was to investigate the efficiency of Curvularia clavata NZ2 in decolorization of azo dyes. The ability of the fungus to decolorize azo dyes can be evaluated as an important outcome as existing effluent treatment is unable to remove the dyes effectively. C. clavata has the ability to decolorize Reactive Black 5 (RB5), Acid Orange 7 (AO7), and Congo Red azo dyes, utilizing these as sole sources of carbon and nitrogen. Ultraviolet-visible (UV-vis) spectroscopy and Fourier infrared spectroscopy (FTIR) analysis of the extracted RB5's metabolites along with desorption tests confirmed that the decolorization process occurred due to degradation and not merely by adsorption. Enzyme activities of extracellular enzymes such as carboxymethylcellulase (CMCase), xylanase, laccase, and manganese peroxidase (MnP) were also detected during the decolorization process. Toxicity expressed as inhibition of germination was reduced significantly in fungal-treated azo dye solution when compared with the control. The cultivation of C. clavata under sequential batch system also recorded a decolorization efficiency of above 90%. The crude enzyme secreted by C. clavata also showed excellent ability to decolorize RB5 solutions with concentrations of 100 ppm (88-92%) and 1000 ppm (70-77%) without redox mediator. This proved that extracellular enzymes produced by C. clavata played a major role in decolorization of RB5. PMID:25850745

  5. Efficient and Convenient Route for the Synthesis of Some New Antipyrinyl Monoazo Dyes: Application to Polyester Fibers and Biological Evaluation

    Directory of Open Access Journals (Sweden)

    Ahmed A. Fadda

    2013-01-01

    Full Text Available Nine variously substituted azo dye derivatives 2–10 of antipyrine were prepared. The effects of the nature and orientation of the substituents on the color and dyeing properties of these dyes for polyester fibers were evaluated. The newly synthesized compounds were characterized on the basis of elemental analyses and spectral data. On the other hand, the investigated dyes were applied to polyester fabrics and showed good light, washing, heat, and acid perspiration fastness. The remarkable degree of brightness after washings is indicative of the good penetration and the excellent affinity of these dyes for the fabric. The results in general revealed the efficiency of the prepared compounds as new monoazo disperse dyes. The newly synthesized compounds were screened for their antioxidant and cytotoxic activity against Vitamin C and 5-fluorouracil, respectively. The data showed clearly that most of the compounds exhibited good antioxidant and cytotoxic activities.

  6. Microstructures and thermochromic characteristics of VO2/AZO composite films

    Science.gov (United States)

    Xiao, Han; Li, Yi; Yuan, Wenrui; Fang, Baoying; Wang, Xiaohua; Hao, Rulong; Wu, Zhengyi; Xu, Tingting; Jiang, Wei; Chen, Peizu

    2016-05-01

    A vanadium dioxide (VO2) thin film was fabricated on a ZnO doped with Al (AZO) conductive glass by magnetron sputtering at room temperature followed by annealing under air atmosphere. The microstructures and optical properties of the thin film were studied. The results showed that the VO2/AZO composite film was poly-crystalline and the AZO layer did not change the preferred growth orientation of VO2. Compared to the VO2 film fabricated on soda-lime glass substrate through the same process and condition, the phase transition temperature of the VO2/AZO composite film was decreased by about 25 °C, thermal hysteresis width narrowed to 6 °C, the visible light transmittance was over 50%, the infrared transmittances before and after phase transition were 21% and 55%, respectively at 1500 nm.

  7. All-Optical Switching Based on Azo Polymer Material

    Institute of Scientific and Technical Information of China (English)

    DENG Yan; LUO Yan-Hua; WANG Pei; LU Yong-Hua; MING Hai; ZhANG Qi-Jing

    2007-01-01

    Conventional all-optical switches based on azo polymer films and the all-optical switches based on the attenuated total reflection (ATR) geometry are investigated. A conventional switch system, including a pump beam of 532nm and a probe beam of 650nm, is based on the photoinduced birefringence effect of azo polymer. An ATR switch in a prism-multilayer configuration is achieved by changing the reflectance of the probe beam with an external pump beam. The ATR method provides the substantial improvement of the speed and the efficiency of the modulation over the conventional method. Although the azo polymer response still remains relatively slow,an enhanced nonlinear refractive index of the azo polymer film can effectively increase the modulation.

  8. Rapid reversible phototuning of lasing frequency in dye-doped cholesteric liquid crystal.

    Science.gov (United States)

    Mykytiuk, T V; Ilchishin, I P; Yaroshchuk, O V; Kravchuk, R M; Li, Y; Li, Q

    2014-11-15

    Lasing in induced cholesteric liquid crystal (CLC) containing highly photosensitive azo chiral dopant (ChD) and pyrromethene laser dye was investigated. Due to the absence of excitation energy transfer from the dye molecules to the molecules of ChD in such a system, a low lasing threshold was achieved. When using violet and green light-emitting diodes, reversible frequency tuning was obtained in the range of about 30 nm with a tuning time 1-2 orders of magnitude smaller than in conventional CLC laser systems based on azo and azoxy photosensitive compounds. Further increase of the intensity of the excitation light by using a green laser pointer allowed us to achieve a record phototuning speed (∼21  nm in 148 ms). PMID:25490501

  9. High flux and antifouling properties of negatively charged membrane for dyeing wastewater treatment by membrane distillation.

    Science.gov (United States)

    An, Alicia Kyoungjin; Guo, Jiaxin; Jeong, Sanghyun; Lee, Eui-Jong; Tabatabai, S Assiyeh Alizadeh; Leiknes, TorOve

    2016-10-15

    This study investigated the applicability of membrane distillation (MD) to treat dyeing wastewater discharged by the textile industry. Four different dyes containing methylene blue (MB), crystal violet (CV), acid red 18 (AR18), and acid yellow 36 (AY36) were tested. Two types of hydrophobic membranes made of polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF) were used. The membranes were characterized by testing against each dye (foulant-foulant) and the membrane-dye (membrane-foulant) interfacial interactions and their mechanisms were identified. The MD membranes possessed negative charges, which facilitated the treatment of acid and azo dyes of the same charge and showed higher fluxes. In addition, PTFE membrane reduced the wettability with higher hydrophobicity of the membrane surface. The PTFE membrane evidenced especially its resistant to dye absorption, as its strong negative charge and chemical structure caused a flake-like (loose) dye-dye structure to form on the membrane surface rather than in the membrane pores. This also enabled the recovery of flux and membrane properties by water flushing (WF), thereby direct-contact MD with PTFE membrane treating 100 mg/L of dye mixtures showed stable flux and superior color removal during five days operation. Thus, MD shows a potential for stable long-term operation in conjunction with a simple membrane cleaning process, and its suitability in dyeing wastewater treatment. PMID:27486044

  10. Draft Genome Sequence of Commercial Textile Dye-Decolorizing and -Degrading Bacillus subtilis Strain C3 Isolated in India

    Science.gov (United States)

    Kunadia, Khushbu; Nathani, Neelam M.; Kothari, Vishal; Kotadia, Rohit J.; Kothari, Charmy R.; Joshi, Anjali; Rank, Jalpa K.; Faldu, Priti R.; Shekar, M. Chandra; Viroja, Mitkumar J.; Patel, Priyank A.; Jadeja, Divyarajsinh; Reddy, Bhaskar; Pal Singh, Ravindra; Koringa, Prakash G.; Joshi, Chaitanya G.

    2016-01-01

    Bacillus subtilis C3, a commercial textile dye-decolorizing and -degrading bacterium, was isolated from the common effluent treatment plant (CEPT) of the Jetpur textile dyeing and printing industrial sector situated in the district of Rajkot, Gujarat, India. Here, we present the annotated 4.18-Mb draft genome sequence of B. subtilis C3, providing information about the metabolic pathways involved in decolorization and degradation of several commercial textile azo dyes. Thus, we confirm B. subtilis C3 as a potential candidate for bioremediation of textile effluents. PMID:26966205

  11. Degradation of Textile Dye Reactive Navy – Blue Rx (Reactive blue–59) by an Isolated Actinomycete Streptomyces krainskii SUK – 5

    OpenAIRE

    Mane, U. V.; Gurav, P. N.; Deshmukh, A.M.; Govindwar, S. P.

    2008-01-01

    The isolated Actinomycete, Streptomyces krainskii, SUK -5 was found to decolorize and degrade textile dye Reactive blue–59.This azo dye was decolorized and degraded completely by Streptomyces krainskii SUK–5 at 24 h in shaking condition in the nutrient medium at pH 8. Induction in the activity of Lignin Peroxidase,and NADH-DCIP Reductase and MR reductase represents their role in degradation .The biodegradation was monitored by TLC, UV vis spectroscopy, FTIR. and GCMS analysis. Microbial and p...

  12. Photoinduced mass transport in azo compounds

    Science.gov (United States)

    Klismeta, K.; Teteris, J.; Aleksejeva, J.

    2013-12-01

    The photoinduced changes of optical properties in azobenzene containing compound thin films were studied under influence of polarized and non-polarized 532 nm laser light. Under influence of light azo compounds experience trans-cis isomerisation process, that can be observed in the absorbance spectrum of the sample. If the light is linearly polarized, molecules align perpendicularly to the electric field vector and as a result photoinduced dichroism and birefringence is obtained. If a known lateral polarization modulation of the light beam is present, mass transport of the azobenzene containing compound occurs. By measuring the surface relief with a profilometer the direction of mass transport can be determined. The studies of this work show that direct holographic recording of surface relief gratings can be used in optoelectronics, telecommunications and data storage.

  13. Hair dye poisoning

    Science.gov (United States)

    Hair dye poisoning occurs when someone swallows dye or tint used to color hair. This article is for ... Different types of hair dye contain different harmful ingredients. ... aromatic amino compounds Phenylenediamines Toluene diamines ...

  14. Eco- and genotoxicological assessments of two reactive textile dyes.

    Science.gov (United States)

    Leme, Daniela Morais; Oliveira, Gisele Augusto Rodrigues de; Meireles, Gabriela; Brito, Lara Barroso; Rodrigues, Laís de Brito; Palma de Oliveira, Danielle

    2015-01-01

    Contamination of natural waters has been one of the major problems of modern society and the textile industry is rated as an important polluting source, due to the generation of large amounts of wastewaters. The aim of this study was to assess textile dyes Reactive Blue 19 (RB19, anthraquinone dye) and Reactive Red 120 (RR120, azo dye) in terms of the potential to induce adverse effects on aquatic organisms and humans. Thus, these dyes were tested using the following assays: Microtox assay (Vibrio fischeri); brine shrimp (Artemia salina); Daphnia similis; and Comet with normal human dermal fibroblasts as well as Ames test (TA98, TA100, YG1041, YG1042--with and without S9). RB19 was relatively nontoxic to all aquatic bioindicators analyzed with an EC50 of more than 100 mg/L, whereas RR120 was only moderately toxic to A. salina with a EC50-48h of 81.89 mg/L. Mutagenicity through base pair substitution was observed with RB19 in the presence of S9 (Ames-positive). The comet assay did not demonstrate any apparent genotoxic effects for any tested dye. Although mutagenicity was detected with RB19, the mutagenic effect observed may be considered weak compared to the ability to induce DNA damage by other classes of dyes such as disperse dyes. Therefore, these dyes may be classified as nonmutagens (RR120) or weak mutagens (RB19) and relatively nontoxic for aquatic organisms. However, it is noteworthy that the weak acute toxicity to A. salina induced by RR120 is sufficient to suggest potential damage to the aquatic ecosystem and emphasizes the need for biomonitoring dye levels in wastewater systems. PMID:25734625

  15. BIOTRANSFORMATION OF TEXTILE DYES: A BIOREMEDIAL ASPECT OF MARINE ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    R. S. Shertate

    2014-01-01

    Full Text Available Presence of huge amount of salts in the wastewater of textile dyeing industry is one of the major limiting factors in the development of an effective biotreatment system for the removal of dyes from textile effluents. Large number of textile industries are located on the coastal areas due to ease of transport to the various places in world and help in building nations economy, but on the contrary the effluents released from these industries are proving a great problem for the marine life. Therefore, industrial effluents containing dyes must be treated before their safe discharge into the environment. There are various physiochemical methods are conventionally used. These methods are effective but quite expensive leading to the production of solid sludge. Bacterial spp. capable of thriving under high salt conditions could be employed for the treatment of saline dye-contaminated textile wastewaters. Most of the Scientists used chemical coagulation, Flocculation and Precipitation techniques for the removal of dye colors from waste waters. But this method is not cost beneficial as it generates huge amount of Sludge and to dispose the sludge is major problem. The physical methods are also not cost effective. So only biological treatment using acclimatized microorganisms could remove 99-100% dye colour from wastewater. Hence now a day most of the workers concentrated on biotransformation of textile azo dyes by adapted organisms. The use of co substrates also slightly increased the decolorization of dye solution. Some scientists showed that the products of dye degradation are not toxic to biological system. Products formed can be determined by Gas Chromatography and Mass Spectroscopy (GC-MS technique, Fourier Transform Infra Red (FTIR etc.

  16. Synthesis, characterization and photoluminescence properties of graphene oxide functionalized with azo molecules

    Indian Academy of Sciences (India)

    R Devi; G Prabhavathi; R Yamuna; S Ramakrishnan; Nikhil K Kothurkar

    2014-01-01

    Two different azo molecules functionalized graphene oxide (GO) through an ester linkage have been synthesized for the first time. Chemical structure of the azo-GO hybrids was confirmed by Fourier transform infrared spectroscopy and UV-visible spectroscopy. The GO functionalized with 5-((4-methoxyphenyl)azo)-salicylaldehyde was further characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The SEM studies demonstrated that the morphology of the azo-GO hybrid was found to be similar to the GO sheets but slightly more wrinkled. Further, TEM image of azo-GO indicates some dark spots on the GO sheets due to azo functionalization. AFM results also reveal that the azo functionalization increases the thickness of GO sheet to 4-5 nm from 1.2-1.8 nm. Both the azo-hybrids show absorption band around 379 nm due to the -* transition of the trans azo units. Photoluminescence spectra of azo-GO hybrids show a strong quenching compared with azo molecules due to the photoinduced electron or energy transfer from the azo chromophore to the GO sheets. It also reveals strong electronic interaction between azo and GO sheets.

  17. Characterization of AZO and Ag based films prepared by RF magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Dagang [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Jiang, Shouxiang, E-mail: kinor.j@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China); Zhao, Hongmei [Department of Prosthodontics, The Affiliated Hospital of Qingdao University, Qingdao (China); Shang, Songmin; Chen, Zhuoming [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)

    2014-12-15

    Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films.

  18. Characterization of AZO and Ag based films prepared by RF magnetron sputtering

    International Nuclear Information System (INIS)

    Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films

  19. Hair dye poisoning

    Science.gov (United States)

    Hair tint poisoning ... Different types of hair dye contain different harmful ingredients. The harmful ingredients in permanent dyes are: Naphthylamine Other aromatic amino compounds Phenylenediamines Toluene ...

  20. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Shasti, M.; Mortezaali, A., E-mail: mortezaali@alzahra.ac.ir; Dariani, R. S. [Department of Physics, Alzahra University, Tehran 1993893973 (Iran, Islamic Republic of)

    2015-01-14

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.